# Professor David Kennedy

MA, PhD, CEng, MBCS, CITP, FRAeS

Professor

- Email:
- kennedyd@cardiff.ac.uk
- Telephone:
- +44 (0)29 2087 5340
- Fax:
- +44 (0)29 2087 4939
- Location:
- S/0.20, Queen's Buildings - South Building, 5 The Parade, Newport Road, Cardiff, CF24 3AA

- Welsh speaking
- Available for postgraduate supervision

Professor of Structural Engineering with expertise in buckling, vibration, optimisation, composite materitals, damage modelling and detection. Developed exact strip software (VICONOPT) for analysis and optimum design of lightweight aircraft structures.

Graduated from Cambridge University in 1978, PhD from Cardiff in 1994.

Chartered Engineer, Fellow of the Royal Aeronautical Society, Member of the British Computer Society.

Deputy Director (Staff) in the School of Engineering (2010-2017).

Director of Postgraduate Reseach Studies (2003-2007).

Collaborative research with Airbus, NASA, Tsinghua University and Dalian University of Technology.

**Qualifications**

PhD, University of Wales, Structural Engineering, 1994.

B.A, Cambridge University, Mathematics / Engineering, 1978.

**Other Expertise**

In my previous employment at Scicon Ltd, I was engaged in the development and support of the mathematical programming system SCICONIC/ VM. With support from the BP Venture Research Unit, I spent 2 years carrying out research into methods for nonlinear optimisation. Some of the resulting special problem structures and techniques to improve the branch and board search were incorporated in SCICONIC/VM.

**Industrial Relevance**

Aerospace industry. Automotive industry.

**Languages (Reading, Writing, Speaking)**

English: (fluent, fluent, fluent)

French: (basic, basic, basic)

Welsh: (basic, basic, basic)

### Professional memberships

- American Institute of Aeronautics and Astronautics (Senior Member)
- British Computer Society (Member)
- Chartered Engineer, Engineering Council
- Chartered IT Professional
- Royal Aeronautical Society (Fellow)

### Academic positions

2005-2009, Reader, Cardiff University, Structural Engineering

2000-2005, Senior Lecturer, Cardiff University, Structural Engineering

1991-2000, Lecturer, Cardiff University, Structural Engineering

1987-1993, Senior Research Associate, Cardiff University, Structural Engineering

1983-1987, Research Associate, Cardiff University, Civil Engineering and Building Technology

1978-1983, Scicon Ltd, Analyst/Programmer

1981-1983, Scicon Ltd, BP Venture Research Fellow

### Committees and reviewing

Editorial Board, Computers and Structures

Editorial Board, Journal of Sound and Vibration

EPSRC Peer Review Panel

### 2019

- Bai, Y.et al. 2019. Numerical predictions of wind induced buffeting vibration for structures by a developed pseudo excitation method. Journal of Low Frequency Noise, Vibration and Active Control 38(2), pp. 510-526. (10.1177/1461348419828248)
- Gao, R., Zhang, Y. and Kennedy, D. 2019. Topology optimization of sound absorbing layer for the mid-frequency vibration of vibro-acoustic systems. Structural and Multidisciplinary Optimization 59(5), pp. 1733-1746. (10.1007/s00158-018-2156-3)
- Gao, R., Zhang, Y. and Kennedy, D. 2019. Reduction of hybrid FE-SEA model for the mid-frequency vibration of vibro-acoustic systems using dynamic condensation approach. Journal of Vibration and Acoustics 141(4), article number: 41007. (10.1115/1.4042930)
- Yahui, Z., Yuyin, L. and Kennedy, D. 2019. An uncertain computational model for random vibration analysis of subsea pipelines subjected to spatially varying ground motions. Engineering Structures 183, pp. 550-561. (10.1016/j.engstruct.2019.01.031)
- Suliman, B., Featherston, C. and Kennedy, D. 2019. A hybrid method for modelling damage in composites and its effect on natural frequency. Computers and Structures 213, pp. 40-50. (10.1016/j.compstruc.2018.12.003)
- Sun, X., Zhang, Y. and Kennedy, D. 2019. On stochastic dynamic analysis and assessment of bistable structures. Nonlinear Dynamics 95(4), pp. 3205-3218. (10.1007/s11071-018-04750-4)
- Liu, X., Featherston, C. A. and Kennedy, D. 2019. Two-level layup optimization of composite laminate using lamination parameters. Composite Structures 211, pp. 337-350. (10.1016/j.compstruct.2018.12.054)

### 2018

- Gao, R., Zhang, Y. and Kennedy, D. 2018. A hybrid boundary element-statistical energy analysis for the mid-frequency vibration of vibro-acoustic systems. Computers and Structures 203, pp. 34-42. (10.1016/j.compstruc.2018.05.007)
- Zhao, Y.et al. 2018. Nonstationary seismic response analysis of long-span structures by frequency domain method considering wave passage effect. Soil Dynamics and Earthquake Engineering 109, pp. 1-9. (10.1016/j.soildyn.2018.02.029)
- Li, Y., Zhang, Y. and Kennedy, D. 2018. Reliability analysis of subsea pipelines under spatially varying ground motions by using subset simulation. Reliability Engineering & System Safety 172, pp. 74-83. (10.1016/j.ress.2017.12.006)
- Damghani, M., Harrison, C. and Kennedy, D. 2018. The effects of composite laminate stiffness and loading on stress resultant concentration factor around a hole. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232(6), pp. 1033-1049. (10.1177/0954406218755187)
- Wang, X., Zhu, H. and Kennedy, D. 2018. Effects of crosslink geometry on the elastic properties of nano-structured biopolymer networks. Presented at: 6th European Conferences on Computational Mechanics, Glasgow, UK, 10-15 June 2018.

### 2017

- Yuyin, L., Yahui, Z. and Kennedy, D. 2017. Random vibration analysis of axially compressed cylindrical shells under turbulent boundary layer in a symplectic system. Journal of Sound and Vibration 406, pp. 161-180. (10.1016/j.jsv.2017.06.018)
- Lei, S., Zheng, X. Y. and Kennedy, D. 2017. Dynamic response of a deepwater riser subjected to combined axial and transverse excitation by the nonlinear coupled model. International Journal of Non-Linear Mechanics 97, pp. 68-77. (10.1016/j.ijnonlinmec.2017.09.001)
- Suliman, B., Featherston, C. and Kennedy, D. 2017. Reduced order techniques for modelling the effects of damage in composite plates. Presented at: ICCM International Conferences on Composite Materials, Xi'an, China, 20-25 Aug 2017.
- Yuan, S.et al. 2017. Adaptive finite element method for eigensolutions of regular second and fourth order Sturm-Liouville problems via the element energy projection technique. Engineering Computations 34(8), pp. 2862-2876. (10.1108/EC-03-2017-0090)
- Yusuke, M., Sinniah, I. and Kennedy, D. 2017. Attaching negative structures to model cut-outs in the vibration analysis of structures. Computers and Structures 184, pp. 14-24.

### 2016

- Kennedy, D.et al. 2016. Equivalent layered models for functionally graded plates. Computers & Structures 174, pp. 113-121. (10.1016/j.compstruc.2015.09.009)
- Kennedy, D., Rios, J. and Ilanko, S. 2016. Decoupling severity and location from cracked beams. Presented at: 23rd International Congress on Sound and Vibration, Athens, Greece, 10-14 July, 201623rd International Congress on Sound and Vibration 2016 (ICSV 23): From Ancient to Modern Acoustics. Auburn, AL: International Institute of Acoustics and Vibration pp. 3200-3207.
- You, J. F.et al. 2016. The high strain compression of micro- and nano-sized random irregular honeycombs. Materials Research Express 3(9), article number: 95023. (10.1088/2053-1591/3/9/095023)
- Xu, W.et al. 2016. Vertical random vibration analysis of adjacent building induced by highway traffic load. Advances in Mechanical Engineering 8(8), pp. 1-9. (10.1177/1687814016659181)
- Ma, Y., Zhang, Y. and Kennedy, D. 2016. Energy flow analysis of mid-frequency vibration of coupled plate structures with a hybrid analytical wave and finite element model. Computers & Structures 175, pp. 1-14. (10.1016/j.compstruc.2016.06.007)
- Si, L. T.et al. 2016. A hybrid approach to analyse a beam-soil structure under a moving random load. Journal of Sound and Vibration 382, pp. 179-192. (10.1016/j.jsv.2016.07.012)
- Xiang, P.et al. 2016. Random vibration analysis for coupled vehicle-track systems with uncertain parameters. Engineering Computations 33(2), pp. 443-464. (10.1108/EC-01-2015-0009)
- Kennedy, D. 2016. Decoupling severity and location. Presented at: 23rd International Congress on Sound and Vision, Athens, Greece, 10-14 July 2016.

### 2015

- Ma, Y., Zhang, Y. and Kennedy, D. 2015. A hybrid wave propagation and statistical energy analysis on the mid-frequency vibration of built-up plate systems. Journal of Sound and Vibration 352, pp. 63-79. (10.1016/j.jsv.2015.05.001)
- Labib, A., Kennedy, D. and Featherston, C. A. 2015. Crack localisation in frames using natural frequency degradations. Computers & Structures 157, pp. 51-59. (10.1016/j.compstruc.2015.05.001)
- Bai, Y.et al. 2015. Numerical analysis of thermoacoustic characteristics of components inside a complex aircraft related to the coupling effect of high temperature and random vibration. Journal of Low Frequency Noise Vibration and Active Control 34(2), pp. 119-135. (10.1260/0263-0923.34.2.119)
- Banerjee, J. R.et al. 2015. Dynamic stiffness matrix of a rectangular plate for the general case. Journal of Sound and Vibration 342, pp. 177-199. (10.1016/j.jsv.2014.12.031)
- Zhang, Z.et al. 2015. Compressed stability analysis of the coupler and buffer system of heavy-haul locomotives. Vehicle System Dynamics, International Journal of Vehicle Mechanics and Mobility 53(6), pp. 833-855. (10.1080/00423114.2015.1023318)
- Ma, Y., Zhang, Y. and Kennedy, D. 2015. A symplectic analytical wave based method for the wave propagation and steady state forced vibration of rectangular thin plates. Journal of Sound and Vibration 339, pp. 196-214. (10.1016/j.jsv.2014.11.029)
- Camotim, D.et al. 2015. Special issue editorial. Computers and Structures 147, pp. 1-3. (10.1016/j.compstruc.2014.11.005)
- Cheng, X.et al. 2015. Localization of delamination in plate structures using natural frequency measurement. Journal of Vibration, Measurement and Diagnosis(3), pp. 535-540.
- De Los Rios, J. and Kennedy, D. 2015. Identification of cracks and temperature in restrained beams using dynamic stiffness matrix. Presented at: 10th International Symposium on Vibrations of Continuous Systems, Estes Park, CO, 26-31 July 2015.

### 2014

- Banerjee, J. R. and Kennedy, D. 2014. Dynamic stiffness method for inplane free vibration of rotating beams including Coriolis effects. Journal of Sound and Vibration 333(26), pp. 7299-7312. (10.1016/j.jsv.2014.08.019)
- Labib, A., Kennedy, D. and Featherston, C. A. 2014. Free vibration analysis of beams and frames with multiple cracks for damage detection. Journal of Sound and Vibration 333(20), pp. 4991-5003. (10.1016/j.jsv.2014.05.015)
- Yuan, S.et al. 2014. Solution of regular second- and fourth-order Sturm-Liouville problems by exact dynamic stiffness method analogy. Journal of Engineering Mathematics 86(1), pp. 157-173. (10.1007/s10665-013-9646-5)
- Zhu, D.et al. 2014. Stochastic vibration of the vehicle-bridge system subject to non-uniform ground motions. Vehicle System Dynamics, International Journal of Vehicle Mechanics and Mobility 52(3), pp. 410-428. (10.1080/00423114.2014.886707)
- Lei, S.et al. 2014. Frequency domain response of a parametrically excited riser under random wave forces. Journal of Sound and Vibration 333(2), pp. 485-498. (10.1016/j.jsv.2013.09.025)
- Zhu, H.et al. 2014. The elastic and geometrical properties of micro- and nano-structured hierarchical random irregular honeycombs. Journal of Materials Science 49(16), pp. 5690-5702. (10.1007/s10853-014-8288-y)
- Damghani, M., Kennedy, D. and Featherston, C. A. 2014. Global buckling of composite plates containing rectangular delaminations using exact stiffness analysis and smearing method. Computers & Structures 134, pp. 32-47. (10.1016/j.compstruc.2013.12.005)
- Zhang, H.et al. 2014. Modeling the high strain compression of nano-sized random irregular Voronoi honeycombs. Presented at: 8th International Conference on Advanced Computational Engineering and Experimenting, Paris, France, June 30-3 July 2014.
- Kennedy, D., Wei, S. and Alcazar Arevalo, F. 2014. Two layer model of functionally graded plate with varying Poisson's ratio. Presented at: CST2014: The Twelfth International Conference on Computational Structures Technology, Naples, Italy, 2-5 September 2014 Presented at Topping, B. H. V. and Ivanyi, P. eds.CCP: 106 Proceedings Of The Twelfth International Conference On Computational Structures Technology, Vol. 106. pp. 34., (10.4203/ccp.106.34)

### 2013

- Ma, C.et al. 2013. Non-stationary seismic response analysis of base-isolated buildings with many hysteretic devices. Computers & Structures 123, pp. 39-47. (10.1016/j.compstruc.2013.04.003)
- Zhang, J.et al. 2013. Non-stationary random vibration of a coupled vehicle-slab track system using a parallel algorithm based on the pseudo excitation method. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 227(3), pp. 203-216. (10.1177/0954409712458403)
- Zhang, H.et al. 2013. Effects of cell irregularity on the elastic properties of nano-sized honeycombs. Presented at: 13th International Conference on Computational Mechanics CM13, Durham, UK, 25-27 March 2013.
- Bai, Y.et al. 2013. Numerical aerodynamic analysis of bluff bodies at a high Reynolds number with three-dimensional CFD modeling. Science China Physics, Mechanics and Astronomy 56(2), pp. 277-289. (10.1007/s11433-012-4982-4)
- Ilanko, S.et al. 2013. Modelling voids using embedded negative structures - the story of the spurious modes. Presented at: International Symposium on Vibrations of Continuous Systems, Courmayeur, Italy, 22 - 26 July 2013Proceedings of the 9th International Symposium on Vibrations of Continuous Systems. pp. 34-36.
- Kennedy, D., Ilanko, S. and Mochida, Y. 2013. Understanding spurious modes of structures with voids using dynamic stiffness method. Presented at: 9th International symposium on Vibrations of Continuous Systems, Courmayeur, Italy, 21 - 26 July 2013Proceedings of the 9th International symposium on Vibrations of Continuous Systems. pp. 37-39.
- Labib, A., Kennedy, D. and Featherston, C. A. 2013. Natural frequencies of beams and frames with concentrated open cracks. Presented at: 9th International Symposium on Vibrations of Continuous Systems, Courmayeur, Italy, 21-26 July 2013Proceedings of the 9th International Symposium on Vibrations of Continuous Systems. pp. 43-45.

### 2012

- El-Kaabazi, N. and Kennedy, D. 2012. Calculation of natural frequencies and vibration modes of variable thickness cylindrical shells using the Wittrick-Williams algorithm. Computers & Structures 104-5, pp. 4-12. (10.1016/j.compstruc.2012.03.011)
- Ilanko, S., Kennedy, D. and Topping, B. 2012. Special Issue: Eigenvalues of continuous systems. Computers & Structures 104-10, pp. Pages 3. (10.1016/j.compstruc.2012.05.006)
- Qu, S., Kennedy, D. and Featherston, C. A. 2012. A multilevel framework for optimization of an aircraft wing incorporating postbuckling effects. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 226(7), pp. 830-845. (10.1177/0954410011415158)
- Wood, O.et al. 2012. Optimised Vibration Energy Harvesting for Aerospace Applications. Key Engineering Materials 518, pp. 246-260. (10.4028/www.scientific.net/KEM.518.246)
- Fischer, M., Kennedy, D. and Featherston, C. A. 2012. Multilevel framework for optimization of lightweight structures. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 226(4), pp. 380-394. (10.1177/0954410011411637)
- York, C. and Kennedy, D. 2012. Application of quasi-homogeneous anisotropic laminates in grid-stiffened panel design. Presented at: 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Honolulu, USA, 23 -26 April 2012.
- Bai, Y.et al. 2012. Numerical aerodynamic simulations of a NACA airfoil using CFD with block-iterative coupling and turbulence modelling. International Journal of Computational Fluid Dynamics 26(2), pp. 119-132. (10.1080/10618562.2011.646997)
- Kennedy, D. 2012. Dynamic stiffness analysis of graphene sheets and carbon nanotubes. Presented at: Eleventh International Conference on Computational Structures Technology, Dubrovnik, Croatia, 4-7 September 2012Proceedings of the Eleventh International Conference on Computational Structures Technology. Stirling: Civil-Comp Press pp. Paper 99., (10.4203/ccp.99.99)
- Kennedy, D. and Cheng, R. K. H. 2012. An equivalent isotropic model for functionally graded plates. Presented at: Eleventh International Conference on Computational Structures Technology, Dubrovnik, Croatia, 4-7 September 2012Proceedings of the Eleventh International Conference on Computational Structures Technology, Vol. 99. Stirling: Civil-Comp Press pp. Paper 94., (10.4203/ccp.99.94)
- Song, G.et al. 2012. An efficient stochastic optimal control algorithm for vehicle suspensions. Presented at: 2012 IEEE International Conference on Computer Science and Automation Engineering (CSAE), Zhangjiajie, China, 25-27 May 2012Computer Science and Automation Engineering (CSAE), 2012 IEEE International Conference on. IEEE pp. 614-620., (10.1109/CSAE.2012.6272846)
- Che, B., Kennedy, D. and Featherston, C. A. 2012. Improved exact strip postbuckling analysis for anisotropic plates. Presented at: 2nd RAeS/CEAS Aircraft Structural Design Conference, London, UK, 26 - 28 October 2010Proceedings of 2nd RAeS/CEAS Aircraft Structural Design Conference. pp. 1-14.

### 2011

- Damghani, M., Kennedy, D. and Featherston, C. A. 2011. Critical buckling of delaminated composite plates using exact stiffness analysis. Computers & Structures 89(13-14), pp. 1286-1294. (10.1016/j.compstruc.2011.04.003)
- Kennedy, D. and Rabbi, R. E. 2011. Vibration of damaged structures using a hybrid continuous and finite element model. Presented at: 8th International Symposium on Vibrations of Continuous Systems, Whistler, BC, Canada, 18-22 July 2011Proceedings of the 8th International Symposium on Vibrations of Continuous Systems, Whistler, Canada. pp. 28-30.
- Xu, W. T.et al. 2011. Sensitivity analysis and optimization of vehicle-bridge systems based on combined PEM-PIM strategy. Computers and Structures 89(3-4), pp. 339-345. (10.1016/j.compstruc.2010.11.011)
- Zhang, Y. W., Lin, J. H. and Kennedy, D. 2011. FEM-based symplectic random vibration analysis of coupled vehicle-track systems. Presented at: 8th International Conference on Structural Dynamics, Leuven, Belgium, 4-6 July 2011 Presented at De Roeck, G. et al. eds.Proceedings of the 8th International Conference on Structural Dynamics, EURODYN 2011. European Association of Structural Dynamics (EASD) pp. 2727-2734.

### 2010

- Sun, W.et al. 2010. Ride-comfort-oriented suspension optimization using the pseudo-excitation method. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 224(11), pp. 1357-1367. (10.1243/09544070JAUTO1417)
- Qu, S., Kennedy, D. and Featherston, C. A. 2010. Multilevel postbuckling design of aircraft wing using VICONOPT MLO. Presented at: Proceedings of 3rd International Conference on Modelling, Simulation and Optimization, Beijing, China. pp. 111-114.
- Williams, F. W. and Kennedy, D. 2010. Historic, Recent and Ongoing Applications of the Wittrick-Williams Algorithm. Computational Technology Reviews 2, pp. 223-246. (10.4203/ctr.2.10)
- El-Kaabazi, N. H. and Kennedy, D. 2010. Natural frequencies of tapered cylindrical shells by Wittrick-Williams algorithm [Paper 189]. Presented at: 10th International Conference on Computational Structures Technology, Valencia, Spain, 14-17 September 2010 Presented at Topping, B. H. V. et al. eds.Proceedings of the Tenth International Conference on Computational Structures Technology. Civil-Comp Proceedings Vol. 93. Stirlingshire, UK: Civil-Comp Press, (10.4203/ccp.93.189)
- Kennedy, D., Park, B. and Unsworth, M. D. 2010. Towards global layup optimization of composite panels with initial buckling constraints. Presented at: 8th ASMO UK Conference on Engineering Design Optimization, London, 8-9 July 2010 Presented at Duddeck, F. et al. eds.Proceedings of the 8th ASMO UK / ISSMO conference on Engineering Design Optimization. University of Leeds: ASMO-UK pp. 221-231.
- Che, B., Kennedy, D. and Featherston, C. A. 2010. Improved exact strip postbuckling analysis for anisotropic plates with fixed, free and straight edges. Presented at: 28th International Congress of the Aeronautical Sciences, Brisbane, Australia, 23 - 28 September 2010Proceedings of 28th Congress of the Aeronautical Sciences. pp. 1-15.
- Kennedy, D. and Featherston, C. A. 2010. Exact strip analysis and optimum design of aerospace structures. Aeronautical Journal 114(1158), pp. 505-512.

### 2009

- Lu, F.et al. 2009. An algorithm to study non-stationary random vibrations of vehicle-bridge systems. Computers & Structures 87(3-4), pp. 177-185. (10.1016/j.compstruc.2008.10.004)
- Xu, W. T.et al. 2009. 2D moving element method for random vibration analysis of vehicles on Kirchhoff plate with Kelvin foundation. Latin American Journal of Solids and Structures 6(2), pp. 169-183.
- Xu, W. T.et al. 2009. Pseudo-excitation-method-based sensitivity analysis and optimization for vehicle ride comfort. Engineering Optimization 41(7), pp. 699-711. (10.1080/03052150902752066)
- Yu, X.et al. 2009. Discrete time-delay optimal control of structures under seismic excitations using the balanced reduction scheme. Journal of Vibration and Control 15(3), pp. 465-478. (10.1177/1077546307078248)
- Lu, F.et al. 2009. Non-stationary random vibration of FE structures subjected to moving loads. Shock and Vibration 16(3), pp. 291-305. (10.3233/SAV-2009-0469)
- Damghani, M., Kennedy, D. and Featherston, C. A. 2009. Global buckling behaviour of composite plates containing embedded rectangular delaminations using exact stiffness analysis. Presented at: Proceedings of CEAS European Air and Space Conference, Manchester, UK. pp. 1-15.
- Watson, A.et al. 2009. Postbuckled stability of panels with torsional buckling mode. Presented at: 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials Conference, Palm Springs, CA, USA, 4 - 7 May 2009Proceedings of the 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference (Palm Springs, USA). American Institute of Aeronautics and Astronautics (AIAA) pp. 1-10., (10.2514/6.2009-2510)
- Yuan, S.et al. 2009. Implementation and evaluation of exact dynamic stiffness method for free vibration of non-uniform beams. Presented at: Proceedings of the 7th International Symposium on Vibrations of Continuous Systems, Zakopane, Poland. pp. 33-35.
- Qu, S., Kennedy, D. and Featherston, C. A. 2009. Multilevel optimisation of an aircraft wing incorporating postbuckling effects. Presented at: Proceedings of CEAS European Air and Space Conference, Manchester, UK.

### 2008

- Lu, F.et al. 2008. Symplectic analysis of vertical random vibration of coupled vehicle-track systems. Journal of Sound and Vibration 317(1-2), pp. 236-249. (10.1016/j.jsv.2008.03.004)
- Kim, H., Kennedy, D. and Gürdal, Z. 2008. Special Issue on Optimization of Aerospace Structures. Structural and Multidisciplinary Optimization 36(1), pp. 1-2. (10.1007/s00158-008-0256-1)
- Qu, S., Kennedy, D. and Featherston, C. A. 2008. Multilevel postbuckling design of aerospace structures. Presented at: Proceedings of 8th World Congress on Computational Mechanics and 5th European Congress on Computational Methods in Applied Sciences and Engineering, Venice, Italy. Vol. A1472. pp. 2.
- Featherston, C. A., Kennedy, D. and Qu, S. 2008. Multi-level postbuckling optimum design of aerospace structures. Presented at: Proceedings of 2nd International Conference on Buckling and Postbuckling Behaviour of Composite Laminated Shell Structures, Braunschweig, German.
- Anderson, M. S. and Kennedy, D. 2008. Postbuckling of composite stiffened panels using exact strip analysis with Newton iteration. Presented at: Proceedings 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Schaumburg, USA. Vol. AIAA-2.
- Kennedy, D.et al. 2008. Postbuckling optimum design of aerospace structures: a multi-level approach. Presented at: Proceedings of the 7th International ASMO-UK/ISSMO International Conference on Engineering Design Optimization, Bath, UK. Vol. 87. pp. 88.
- LIn, J. H.et al. 2008. An accurate and efficient algorithm for the response of bridges subjected to moving loads by the precise integration method. In: Lin, J. H. and Zhong, W. X. eds. Simplectic mathematics, precise integration, random vibration and applications: selected papers for frontier problems in modern science and technology.. Hefei, China: University of Science and Technology of China Press
- Song, G.et al. 2008. An efficient stochastic optimal control algorithm for vehicle suspensions. In: Lin, J. H. and Zhong, W. X. eds. Simpletic mathematics, precise integration, random vibration and applications: selected papers for frontier problems in modern science and technology.. Hefei, China: University of Science and Technology of China Press, pp. 357-372.
- Kennedy, D. and Featherston, C. A. 2008. Exact strip analysis and optimum design of aerospace structures. Presented at: RAeS/CEAS Aircraft Structural Design Conference, Liverpool, UK, 14 - 16 October 2008Proceedings of RAeS/CEAS Aircraft Structural Design Conference. pp. 1-12.
- Damghani, M., Featherston, C. A. and Kennedy, D. 2008. Critical buckling of delaminated composite plates using exact stiffness analysis. Presented at: 9th International Conference on Computational Structures Technology, Athens, Greece, 2-5 September 2008 Presented at Topping, B. and Papadrakakis, M. eds.Proceedings of 9th International Conference on Computational Structures Technology (Athens, Greece), Vol. CST.30. Kippen: Civil-Comp Press pp. 1-14.

### 2007

- Kennedy, D., Fischer, M. and Featherston, C. A. 2007. Recent developments in exact strip analysis and optimum design of aerospace structures. Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science 221(4), pp. 399-413. (10.1243/0954406JMES432)
- Yuan, S.et al. 2007. Exact dynamic stiffness method for frames with non-uniform Timoshenko beam vibrations and Bernoulli-Euler column buckling. Journal of Sound and Vibration 303, pp. 526-537. (10.1016/j.jsv.2007.01.036)
- Watson, A., Featherston, C. A. and Kennedy, D. 2007. Optimization of postbuckled stiffened panels with multiple stiffener sizes. Presented at: 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Honolulu, USA. Vol. AIAA-2. pp. 1-8.

### 2006

- Qi, Z., Kennedy, D. and Williams, F. W. 2006. A highly stable and accurate computational method for eigensolutions in structural dynamics. Computer Methods in Applied Mechanics and Engineering 195(33-36), pp. 4050-4059. (10.1016/j.cma.2005.08.007)
- Kennedy, D. 2006. Experiments in optimization using VICONOPT and other software tools. Presented at: Proceedings of the 7th World Congress on Computational Mechanics, Los Angeles, USA. Vol. 1556.
- Kennedy, D., Patel, D. and Featherston, C. A. 2006. Buckling of wing spars under combined loading. Presented at: Proceedings of 25th International Council of the Aeronautical Sciences ICAS Congress, Hamburg, Germany, Vol. 10. Vol. 1. pp. 8.
- Williams, F. W.et al. 2006. Towards a deeper understanding of the Wittrick-Williams algorithm for solving eigenproblems. Presented at: Proceedings of EPMESC X: Computational Methods in Engineering and Science, Sanya, China. Tsinghua University Press & Springer pp. 137-139.

### 2005

- Djoudi, M. S.et al. 2005. Exact substructuring in recursive Newton's method for solving transcendental eigenproblems. Journal of Sound and Vibration 280(3-5), pp. 883-902. (10.1016/j.jsv.2003.12.050)
- Kennedy, D., O'Leary, O. J. and Williams, F. W. 2005. Optimum design of prismatic plate assemblies with spectral gap constraints. Presented at: Proceedings of the 5th International Symposium on Vibrations of Continuous Systems, Berchtesgaden, Germany. pp. 36-38.
- Williams, F. W.et al. 2005. A new relationship between linear and transcendental eigenproblems. Presented at: Proceedings of the 5th International Symposium on Vibrations of Continuous Systems, Berchtesgaden, Germany. pp. 87-89.

### 2004

- Williams, F. W., Kennedy, D. and Djoudi, M. S. 2004. Exact determinant for infinite order FEM representation of a Timoshenko beam-column via improved transcendental member stiffness matrices. International Journal for Numerical Methods in Engineering 59(10), pp. 1355-1371. (10.1002/nme.919)
- Featherston, C. A.et al. 2004. Design rules for panel buckling under combined shear, compression and bending. Presented at: 4th International Conference on Thin-Walled Structures, Loughborough, UK, 22-24 June 2004 Presented at Loughlan, J. ed.Thin-Walled Structures: Advances in Research, Design and Manufacturing Technology. Institute of Physics Publishing pp. 153-160.
- Qi, Z., Kennedy, D. and Williams, F. W. 2004. An accurate method for transcendental eigenproblems with a new criterion for eigenfrequencies. International Journal of Solids and Structures 41(11-12), pp. 3225-3242. (10.1016/j.ijsolstr.2004.01.022)
- Kennedy, D., Ioannidis, G. and Featherston, C. A. 2004. Discrete optimum design of composite plates including longitudinal voids. Presented at: Proceedings of 6th World Congress on Computational Mechanics in conjunction with 2nd Asian Pacific Congress on Computational Mechanics,, Beijing, China. Vol. M636. pp. 10.
- Watson, A. and Kennedy, D. 2004. Mode jumping in post-buckled stiffened panels. Presented at: Proceedings of 4th International Conference on Thin Walled Structures (ICTWS 04), Loughborough, UK.
- Williams, F. W.et al. 2004. Recent transcendental eigensolution advances in structural engineering and other disciplines. Presented at: Proceedings of 6th World Congress on Computational Mechanics in conjunction with the 2nd Asian Pacific Congress on Computational Mechanics, Beijing, China. pp. 734-739.
- York, C. B. and Kennedy, D. 2004. Minimum mass design of composite wing box structures incorporating syntactic core fiber replacement. Presented at: Proceedings of 6th World Congress on Computational Mechanics in Conjunction with 2nd Asian Pacific Congress on Computational Mechanics, Beijing, China. Vol. M639. pp. 10.

### 2003

- Williams, F. W., Kennedy, D. and Djoudi, M. S. 2003. The member stiffness determinant and its uses for the transcendental eigenproblems of structural engineering and other disciplines. Proceedings of The Royal Society A: Mathematical, Physical and Engineering Sciences 459(2032), pp. 1001-1019. (10.1098/rspa.2002.1074)
- Watson, A.et al. 2003. Buckling and vibration of stiffened panels or single plates with clamped ends. Advances in Structural Engineering 6(2), pp. 135-144. (10.1260/136943303769013228)
- Williams, F. W. and Kennedy, D. 2003. Derivation of new transcendental member stiffness determinant for vibrating frames. International Journal of Structural Stability and Dynamics 3(2), pp. 299-305.
- Yuan, S.et al. 2003. Recursive second order convergence method for natural frequencies and modes when using dynamic stiffness matrices. International Journal for Numerical Methods in Engineering 56, pp. 1795-1814. (10.1002/nme.640)
- Kennedy, D., Williams, F. W. and Yuan, S. 2003. Analogies between transcendental and linear eigenproblems.. Presented at: Proceedings of 8th International Conference on Recent Advances in Structural Dynamics, Southampton, UK, Vol. 37. pp. 12.
- Williams, F. W.et al. 2003. A summary of recent and current work on development of transcendental eigensolvers and their applications. Presented at: Proceedings of the 11th International Conference on Computational and Experimental Engineering and Sciences, Corfu, Greece. pp. 6.
- Williams, F. W. and Kennedy, D. 2003. Analogous behaviour of transcendental and linear eigensolutions for free vibration of structures. Presented at: Proceedings of 4th International Symposium on Vibrations of Continuous Systems, Keswick, UK. pp. 57-59.
- Williams, F. W.et al. 2003. Recent discoveries related to the use of the Wittrick-Williams algorithm to solve transcendental eigenproblems. Presented at: Proceedings of the 9th International Conference on Computational Methods in Engineering and Science:, Macao, China. pp. 139-149.
- Zare, A., Howson, W. P. and Kennedy, D. 2003. An overview of member stiffness determinants for prismatic plate assemblies. Presented at: Proceedings of 11th International Conference on Computational and Experimental Engineering and Sciences :Advances in Computational and Experimental Engineering and Sciences, Corfu, Greece, Vol. 340. pp. 6.
- Lillico, M.et al. 2003. Postbuckling of stiffened panels using strut, strip, and finite element methods. AIAA Journal 41(6), pp. 1172-1179. (10.2514/2.2061)

### 2002

- Fischer, M., Kennedy, D. and Featherston, C. A. 2002. Multilevel optimization of a composite aircraft wing using Viconopt MLO. Presented at: 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Atlanta, Georgia, USA, 4-6 September 20029th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization. AIAA, (10.2514/6.2002-5511)
- Williams, F. W.et al. 2002. Towards deep and simple understanding of the transcendental eigenproblem of structural vibrations. Journal of Sound and Vibration 256(4), pp. 681-693. (10.1006/jsvi.2002.5016)
- Lillico, M.et al. 2002. Analysis and testing of a postbuckled stiffened panel. AIAA Journal 40(5), pp. 996-1000.
- Williams, F. W. and Kennedy, D. 2002. An overview of application of the recently discovered member stiffness determinant when solving the transcendental eigenproblems of structural engineering. Presented at: Proceedings of the 2nd International Conference on Structural Stability and Dynamics, Singapore. pp. 243-248.
- Fischer, M., Kennedy, D. and Featherston, C. A. 2002. Multilevel optimization of aerospace and lightweight structures. Presented at: 23rd International Congress of Aeronautical Sciences, Toronto, Canada, 8 - 13 September 2002ICAS 2002: 23rd International Congress of Aeronautical Sciences. International Council of the Aeronautical Sciences(ICAS) pp. 344.1-344.9.

### 2001

- Kennedy, D.et al. 2001. Equivalences between transcendental and linear eigenvalue problems of free structural vibration. Presented at: Proceedings of the 3rd International Symposium on Vibrations of Continuous Systems, Jackson Lake, Wyoming, USA. pp. 36-38.
- O'Leary, O. J., Williams, F. W. and Kennedy, D. 2001. Optimum stiffened panel design with fundamental frequency constraint. Thin-Walled Structures 39(7), pp. 555-569. (10.1016/S0263-8231(01)00022-2)
- Lillico, M.et al. 2001. Post-buckling of single and multi-bay panels using strut, strip and FE methods. Presented at: 42nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials Conference, Seattle, USA, 2001Proceedings 42nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials Conference, Seattle, USA.

### 1997

- Williams, F. W. and Kennedy, D. 1997. VICONOPT: Analysis and design code for prismatic assemblies of laminated plates. In: Final report of the GARTEUR Action Group on Structural Optimisation SM(AG13): A compendium of European Software Facilities for Stiffened Panel Design and Multi-Level Optimisation., Vol. 2. Farnborough: Defence Evaluation and Research Agency (DERA)
- Williams, F. W.et al. 1997. Parametric study of stiffened wing panels of dornier benchmark problem. In: Final report of the GARTEUR Action Group on Structural Optimisation SM(AG13): Assessment of Benchmark Problems on Stiffened Panel Design and Multi-level Optimization., Vol. 3. Farnborough: Defence Evaluation and Research Agency (DERA)
- Williams, F. W., Kennedy, D. and Williams, P. W. L. 1997. Current experience of the use of the stiffened panel design software VICONOPT in optimum design of aircraft. Engineering Optimization 29(1-4), pp. 39-48. (10.1080/03052159708940985)

### 1994

- Kennedy, D., Williams, F. W. and Anderson, M. S. 1994. Buckling and vibration analysis of laminated panels using VICONOPT. Journal of Aerospace Engineering 7(3), pp. 245-262. (10.1061/(ASCE)0893-1321(1994)7:3(245))

### 1993

- Anderson, M. S. and Kennedy, D. 1993. Transverse shear deformation in exact buckling and vibration of composite plate assemblies. AIAA Journal 31(10), pp. 1963-1965. (10.2514/3.11877)
- York, C. B.et al. 1993. A parametric study of optimum designs for benchmark stiffened wing panels. Composites Engineering 3(7-8), pp. 619-632. (10.1016/0961-9526(93)90086-Y)

Engineering Analysis (UG year 2)

Structures and Design (UG year 2)

Structural Engineering (UG year 4 / MSc)

Case Study (MSc)

Research theme: Mechanics, Materials and Advanced Manufacturing

My current research centres on the solution of nonlinear structural eigenvalue problems by exact (as opposed to finite element (FE)) methods. The characteristic approach is to assemble the static or dynamic stiffness matrix of the structure using exact member equations (eg for plane frames, space frames and plate assemblies) and to guarantee convergence on all required eigenvalues by using the Wittrick-Williams algorithm. Collaborative work with the National Aeronautics and Space Administration (NASA) and British Aerospace has led to the release of buckling and vibration programs for 3-dimensional lattice structures (BUNVIS-RG) and for prismatic plate assemblies (VICONOPT). VICONOPT includes a design capability, and is used in the aerospace industry in the UK, Europe and the USA. Particular emphasis has been placed on the efficient implementation of the numerical algorithms used to converge on the eigenvalues, including parallel processing techniques and optimisation strategies. Current research areas include postbuckling analysis, accurate mode-finding methods, discrete optimisation and delamination of carbon-fibre composites.

In 2007 I undertook an industrial secondment at Airbus UK, funded by The Royal Society, developing software tools for the postbuckling analysis of composite aerospace structures.

### Future Research

- Accurate mode-finding techniques using the Wittrick-Williams Algorithm.
- Multi-level optimisation strategies for lightweight structural design.
- Postbuckling of aerospace structures.
- Delamination of carbon-fibre composites.
- Detection of damage via changes in natural frequencies.

### Major Funding Received

Royal Society Industry Fellowship: Software tools for postbuckling of aerospace structures, £24635, Feb 1, 2007 to Sep 30, 2007.

Engineering and Physical Sciences Research Council: Mode finding when using the Wittrick-Williams algorithm, via linear eigensolution analogy, £140229, Jan 11, 2001 to Jan 10, 2004.

Engineering and Physical Sciences Research Council: Initial and advanced post-buckling of optimized stiffened panels, £71763, Nov 23, 1998 to Nov 22, 2000.

Engineering and Physical Sciences Research Council: Algorithms for avoiding local optima in aerospace panel design, £101889, Apr 1, 1994 to Mar 31, 1997.

Science and Engineering Research Council: ITE: New solution methods for exact structural eigenvalue problems using parallel computers, £81487, Jun 22, 1992 to Jun 21, 1995.

### Contracts

Title | People | Sponsor | Value | Duration |
---|---|---|---|---|

Travel grant | Dr D Kennedy | The National Assembly for Wales | 3000 | 01/01/2002 - 01/01/2003 |

Computational mechanics | Dr D Kennedy | Royal Society | 1486 | 05/09/2004 - 15/09/2004 |

Software tools for postbuckling of aerospace structures | Kennedy D | Royal Society | 24635 | 01/02/2007 - 01/10/2007 |

Mode finding when using the Wittrick-Williams algorithm, via linear eigensolution analogy | Prof FW Williams, Dr D Kennedy | Engineering and Physical Sciences Research Council | 140229 | 11/01/2001 - 10/01/2004 |

### Supervised Students

Title | Student | Status | Degree |
---|---|---|---|

Crack Detection In Frames Using Natural Frequency Degradations | LABIB Amr Osama Mostafa | Graduate | PhD |

Modelling of damage in composite stiffened panels | SULIMAN Basem Saoud | Graduate | PhD |

Improved Exact Strip Postbuckling Analysis Of Anisotropic Plate With Combined Load And Edge Cases. | CHE Bin | Graduate | PhD |

Postbuckling analysis of stiffened panels. | ZHANG Chi | Current | PhD |

THE MECHANICAL PROPERTIES OF NANO-SIZED MATERIALS AND STRUCTURES | ZHANG Hongchao | Graduate | PhD |

DESIGN OPTIMISATION OF ADVANCED FIBRE COMPOSITES. | KANG Jiaming | Current | PhD |

Buckling Behaviour of Delaminated Composite Plates Using Exact Stiffness Analysis | DAMGHANI Mahdi | Graduate | PhD |

Multilevel Optimisation of Aerospace and Lightweight Structures | FISCHER Marc | Graduate | PhD |

Computational Modelling of Particlate Composites using Meshless Methods | ISLAM Md Sultanul | Graduate | PhD |

POSTBUCKLING ANALYSIS OF COMPOSITE STIFFENED PANELS LOADED IN COMPRESSION AND SHEAR. SPECIALISATION - CIVIL/STRUCTURAL ENGINEERING. | AL SAYMAREE Muthana Shaker Mahdi | Current | PhD |

DYNAMIC ANALYSIS OF SHELLS | EL KAABAZI Nihal Husein Fouad | Graduate | PhD |

Multilevel Optimisation of Aerospace and Lightweight Structures Incorporating Postbuckling Effects | QU Shuang | Graduate | PhD |

New Generic Algorithms for Constrained Optimisation snd Applications to Design of Composite Laminates | YU Tat Loong (Raymond) | Graduate | PhD |

Multi-storey frames with rigid joint damage detection method based on the second order difference of influence lines | LIU Xiaoyang | Current | PhD |

THE APPLICATION OF VICONOPT SOFTWARE FOR DAMAGE IDENTIFICATION IN PLATE STRUCTURE OF BRIDGE DECK SLAB. | LUO Yulin | Current | PhD |