I am a professional engineer (PE) and a passionate academic with research and teaching experience in the area of materials, solid mechanics, failure analysis and forensic engineering. My core specialization is in composite materials with specific interest in progressive damage modelling and testing of composites at various length scales. Key research experience includes FE based continuum damage modelling, cohesive zone modelling, NDT of composites using X-ray CT, ultrasonic C-Scan and mechanical property testing of 2D and 3D woven composites.
I have over 50 research publications and have won several funded projects. I have experience of teaching a wide range of modules related to materials, solid mechanics, stress and failure analysis, finite element methods and mechanics of composites and forensic engineering at all levels in HEIs.
I have supervised around 50 student thesis and design projects. Lead mechanical department for engineering council accreditation of its BEng program. Lead teams in terms of executing funded projects and for organizing international conferences and carried out knowledge exchange and CPD activities.
My PhD and MSc is from the University of Manchester, UK and have worked on research projects at the University of Bath, University of Cambridge and University of Manchester, UK.
I have taught a range of subjects in materials/mechanical engineering over the years. My current teaching responsibilities include teaching 'Advanced Engineering Materials and Applications', 'Materials and Manufacturing Processes', 'Failure Analysis' and 'Forensic Engineering failure analysis and prevention'
In the past I have taught courses including 'Finite Element Analysis of Composites', 'Mechanics of Composites', 'Finite Element Method', 'Mechanics of Materials I' (solid mechanics 1), 'Mechanics of Materials II' (solid mechanics II' and 'Design of Machine Elements'.
I have also been involved in teaching quality enhancement activities and have re-defined mechanical engineering programmes at NUST and CUST to bring them in line for the Washington accord accreditation.
I have been involved with various professional academic activities such as curriculum development and knowledge exchange activities including organizing conferences, workshops, and training such as:
Progressive damage analysis of composites using ABAQUS™ – 4th -5th March 2015
Lead organizer and speaker for a two-day CPD training course for engineers
Finite Element Analysis of Composites – 7th Nov 2014
Lead organizer and speaker for a half day CPD seminar on FEA of products and structures made from composite materials
Guest Speaker for four-hour session titled; ‘Composites Manufacturing & Manufacturing Process Selection Strategy (the Ashby approach)’ in the CPD activity, ‘1st International Workshop on Cost-Effective Composites Manufacturing’ held at Institute of Space Technology, Islamabad, Pakistan, - 26th Feb – 5th Mar 2014
Lead organizer for a hands-on training workshop on composites manufacturing using vacuum-assisted resin infusion – 02 June 2012
‘Designed for Composites’ – 24th – 25th March 2011
Lead organizer and speaker for a two-day professional training workshop on design of products made from composite materials
Organized Pakistan first-ever Composite Show on Wednesday 5th Dec 2012 at Islamabad Hotel, G-6 Islamabad. The event featured two parallel activities: a. A symposium & a policy dialogue session where around 150 very senior academics, industrialists and government functionaries exchanged views to evolve a strategy for turning around the composites industry of Pakistan. b. An industrial exhibition which featured over 20 companies and attracted over 500 visitors
Supervised several research projects in collaboration with industry
I have a rich and diverse research profile. In the start of my career, my research focused on FE modelling and testing of woven composite’s lap joints subjected to impact loading. Later, I expanded my research portfolio in both depth and breadth. Thus, currently my research and research supervisions falls under the following of five thematic areas.
Progressive damage modelling in composites and composite joints using FE based as well as analytical methods
Micromechanics of composites and multiscale modelling (both FE and analytical modelling)
Software development for composites research, teaching and analysis
Development of Composite testing standards, methods and equipment.
Composites manufacturing and product design
Because of my research experience, I boast the following key research skills:
FE based analysis of woven composites including:
Cohesive zone modelling, micromechanical modelling and continuum damage modelling
Writing my own material models using Fortran subroutines for AbaqusTM
Image-based modelling of composites
Analytical micro-mechanical modelling of composites and programming the analytical models using programming languages such as Matlab and VB.Net
Mechanical and material property testing including fracture toughness testing
Non-destructive testing using X-ray micro CT, ultrasonic C-scan and other techniques
Developing research networks (industry and academia), writing grant proposals and carrying out knowledge exchange activities
Membership of professional bodies
Pakistan Engineering Council (PEC): Professional Engineer (P. Eng.) (Member since 2002)
Institute of Materials (IOM), UK - MIMMM (Member since 2009)
Fellow Higher Education Academy - FHEA (2020)
BE Mechanical Engineering National University of Sciences and Technology (NUST), Pakistan 2002
MS (course work only) Mechanical, National University of Sciences and Technology (NUST), Pakistan 2003
MS Advanced Manufacturing & Systems Mgmt., The University of Manchester Institute of Science and Technology, UK, 2004 – with distinction in dissertation (thesis)
PhD Mechanical Engineering (Composite materials - Impact damage characterization and modelling), The University of Manchester, UK, 2009
R. S. Choudhry, S.Z.H. Shah, Yousaff, Impact Damage Tolerance of Resin Infused Thermoplastic 3D Composites, Thermoplastic Composites 2020, 19th Oct 2020, British Plastics Federation, UK
R. S. Choudhry, Multiscale modelling of DFC Composites, NAFEMS UK Virtual Conference 2020, 9th-10th Nov 2020, NAFEMS
R. S. Choudhry, S.Z.H. Shah, A novel approach for modelling of ROS and ROS-hybrid composites, ICCM 22, 22nd International Conference on Composite Materials, 11 – 16 August 2019, in Melbourne, Australia
R. S. Choudhry, Effect of voids on mechanical properties of woven composites, 13th International Conference on Textile Composites, Texcomp-13, 17-19 September 2018, in Milan, Italy
R. S. Choudhry, L.E. Culliford, , R. Butler, A.T. Rhead, Finite element prediction of tensile and buckling response of discretely stiffened composite panels, Simulia UK RUM 2017 Conference, 18-19th Oct 2017, Park Royal, Cheshire, UK
L.E. Culliford, R. S. Choudhry, R. Butler, A.T. Rhead, Discrete Stiffness Tailoring for improved Buckling Performance, ICCM 21, 21st International Conference on Composite Materials, 20 – 25 August 2017, in Xi’an China
X. Lei, K. Hayat, M.T. Hussain, H.T. Ali, R.S. Choudhry A numerical study on the impact resistance of braided composites, Fourth International Conference of Aerospace Science and Engineering (ICASE2015), September 2 – 4, 2015, Institute of Space Technology (IST), Islamabad, Pakistan
Determination of Key Mechanical Properties for Simulating Delamination Damage in Impacted Bonded Joints of Composites, R S Choudhry, S Li, R Day, S F Hassan, Proceedings of American Society of Composites-30th Technical Conference September 28-30, 2015, Michigan State University, Michigan, USA
K. Miura, M. Kashiwagi, K. Esaki, R.S. Choudhry, J.L.Y Tan, V.S. Deshpande. N. Fleck, OS1407 Fracture Behavior of CFRP Structure from Stress-raising Defects under Combined Loading, The Proceedings of the Materials and Mechanics Conference, The Japan Society of Mechanical Engineers, July 2014
Tanveer Ahmed, R.S. Choudhry, Himayat Ullah, Fahad Hassan, Numerical modelling of carbon fibre reinforced polymer composites for hole size effect, APCoMS-3, 3rd ASEAN-Pakistan Conference on Materials Science, 25-27 November 2014, National University of Sciences and Technology (NUST), Islamabad, Pakistan
J L.Tan, N A.Fleck, V. Deshpande, R.S. Choudhry, K. Esaki et al., Investigating the damage mechanisms and their effects on the notch sensitivities of cross-ply CFRP laminates under uniaxial loading Proceedings 16th European Conference on Composite Materials, 22-26 June 2014, Seville, Spain
MPF Stutcliffe, C Monroy Aceves, WJ Stronge, R. S. Choudhry, AE Scott, L Lobo, Low-speed impact damage in hybrid 2D-braided composite plates, TexComp 2010, International Conference on Textile Composites (10th Ed), 26-28 October 2010, Lille Grand Palais, France
R. S. Choudhry, R. Day, S. Li, Characterization of impact induced damage modes in composites using X-ray microtomography, ICCM 17, 17th International Conference on Composite Materials, 27-31 Jul 2009, Edinburgh, UK ()
P. Potluri, T Sharif, D Jetavat, A Aktas, R Choudhry, P Hogg, Bench marking of 3D performing strategies, ICCM 17, 17th International Conference on Composite Materials, 27-31 Jul 2009, Edinburgh, UK
R. S. Choudhry, P. Hogg, X Ray Tomography – A Powerful NDT Technique for Assessing Structural Parts, 9th Annual Conference: Innovation in Composites, 29th – 30th April 2009, Manchester Conference Centre, UK
R. S. Choudhry, R. Day, S. Li, Modelling failure and damage growth in lap joints of woven GFRP composites – A comparison of failure modes, DFC-10, 10th Deformation and Fracture of Composites Conference, 15th – 17thApril 2009, Kroto Research Institute, Sheffield, UK
R. S. Choudhry, R. Day, S. Li, Impact induced damage in Quickstep cured lap joints of woven fibre reinforced composites, ICMAC 2009, International Conference for Manufacturing of Advanced Composites, 18-19 March 2009, Belfast Waterfront, UK
R. S. Choudhry, R. Day, S. Li, Failure Analysis of Composites and Lap Joints of Composites, PGR-MACE 09, Postgraduate Research Conference, The University of Manchester, 11th June 2009, pp 8-9
R. S. Choudhry, R. Day, S. Li, Impact Damage in Bonded Joints of Woven Composites, NWCC Annual Conference, 26th January 2009, Manchester, UK
Experience in industry
Effective research collaboration and partnership with industry underpins success for academics. My experience of collaborative research and industrial engagement is at various levels. For example, my Post-Doctoral experience at all three Universities where I carried out research (The University of Bath, The University of Cambridge and The University of Manchester) was on projects that were heavily sponsored through the industries.
For example, the Cambridge project was funded by Mitsubishi Heavy Industries (MHI), Japan and the Manchester project was funded by the Ministry of Defence (MOD), UK, respectively. The project at Bath was an EPSRC project however it also involved GKN and Airbus as industrial partners. As part of the project at Cambridge, I was involved in direct discussions and reporting to MHI on project deliverables while the work in Manchester required me to report my findings to MOD and Nanoforce. In addition, during the period of my Post Doc in Manchester, I also performed contract work on behalf of NCCEF, University of Manchester for industry clients such as Brook House for X-ray CT work.
Several of my undergrad and postgrad projects have been completed with active partnership and help from local industries. As for example the three MSc projects related to developing testing standards of composites required active collaboration with our colleagues at NESCOM for completion. Another MSc thesis titled ‘Enhancement of mechanical properties of woven glass epoxy composites using aligned multiwall carbon nanotubes’ supervised by me, was based on the requirements posed by our industrial partner in a public sector aerospace manufacturing setup (AWC, NESCOM).
In this project, we worked on a novel method of using a magnetic field for the alignment of carbon nanotubes during vacuum-assisted resin infusion. Another example of collaborative project supervision includes supervision of two projects funded by heavy industries Taxila, for development of high-speed impact testing facility for body armor materials. In a similar manner my supervised BE project titled, ‘Indigenous development of pre-preg manufacturing machine for Uni-directional composites’ is a result of my interaction with the hockey stick manufacturers association of Pakistan and in Particular with Grays of Cambridge, who are the largest exporters of hockey sticks from Pakistan and extensively use in-house produced pre-preg for the production of their hockey sticks.
While reading the above examples, it must be kept in mind that all these projects have been completed with industry support in a third world country (developing country) where the culture of academic / industry collaboration is much less developed.
I have worked in both Pakistan and Britain, and have carried out international collaborations on research projects in Malaysia, Japan, UAE and USA. Some of the universities that I worked in, followed the British system while others followed the US systems. My international accomplishments include:
International Faculty Achievement Award (IAUP - NUST) 2014 Winner International Association of University Presidents (IAUP), International Faculty Achievement Award of NUST for the year 2014.
Project Lead for the British Council - DFID sponsored award under the DelPHE scheeme titled, 'Capacity building for enhancing R&D in manufacturing, testing and certification of composite materials'
The project established a bilateral partnership between NUST department of Mechanical Engineering and National Composites Certification and Evaluation Facility at the University of Manchester, UK to improve capacity for carrying out high impact research in the area of composite materials with the long-term objective of contributing towards the attainment of millennium development goals of poverty reduction through industrial innovation. Thus, the key objective of the project was imparting training in design, manufacturing, testing and certification through workshops and seminars at three levels i.e. policymakers, academics and students.
It also aimed at enabling student/faculty exchange between NUST and Manchester through internship and guest researcher program. A countrywide survey for requirements analysis for establishing R&D centre for composites manufacturing evaluation and certification was carried out as part of the project and report was presented to government and private industries during the Pakistan Composite Show and Policy Dialogue organised by PI as part of this project. The project resulted in introduction of new MSc/PhD level course in NUST curriculum, it increased awareness of the research and business potential for advanced composites and resulted in establishment of composites engineering research group.
Co-PI for the British Council - sponsored award under the InSPIRE - SPEKE scheeme titled, 'Sustainable energy solution for rural communities through community participation'
The project built on the existing strategic partnership with British and Pakistani Universities (INSPIRE) by focusing on two new objectives. On one hand it aims at using the theoretical and lab results of the existing project to create a demonstrator unit with the help of local industry (Chitral engineering works) and installing this demonstrator on a canal in rural areas leased from the KPK/Punjab government. On the other hand it aims at increasing the acceptance of technology in the rural communities and motivating school and college students for getting science and technology education, and convincing them of the positive role technology can play in their lives.
In addition I have ongoing international collaborations with University Petronas Malaysia and Khalifa University UAE.
Talk at Thermoplastic Composites 2020, 19th Oct 2020, British Plastics Federation, UK (recording available online)
S.Z.H Shah, P. S. M. M. Yusoff, S Karuppanan, R.S. Choudhry, Compression and buckling after impact response of resin-infused thermoplastic and thermoset 3D woven composites. Composites Part B: Engineering, Volume 207, 15 February 2021, 108592 https://doi.org/10.1016/j.compositesb.2020.108592 (ISI indexed)
P. S. M. M. Yusoff, S.Z.H Shah, S Karuppanan, R.S. Choudhry, F. Ahmad, Z. Sajid, P. Gerard, K. Sharp, Performance comparison of resin-infused thermoplastic and thermoset 3D fabric composites under impact loading, International Journal of Mechanical Sciences, Available Online 29th July 2020, https://doi.org/10.1016/j.ijmecsci.2020.105984 (ISI indexed)
S.Z.H Shah, R.S. Choudhry, S. Mahadzir A new approach for strength and stiffness prediction of discontinuous fibre-reinforced composites (DFC), Composites Part B: Engineering, vol. 183, Feb 2020, pp.107676, https://doi.org/10.1016/j.compositesb.2019.107676 (ISI indexed)
L. Culliford, R. S. Choudhry, R. Butler, A.T. Rhead, Buckling and Strength Analysis of panels with Discrete Stiffness Tailoring, Composite Structures, vol. 234, Feb 2020, pp.111672, https://doi.org/10.1016/j.compstruct.2019.111672 (ISI indexed)
R. S. Choudhry, Tahir Sharif, Kamran A. Khan, Sohaib Z Khan, Abid Hassan, Muhammad A Khan, Predicting the effect of voids on mechanical properties of woven composites, IOP Conference Series: Materials Science and Engineering, vol. 406, (2018), pp: 012007, DOI: https://doi.org/10.1088/1757-899X/406/1/012007 , ISSN 1757-899X. (ISI indexed)
T Sharif, P Potluri, R. S. Choudhry, A Dodworth, Forming low-cost, high quality carbon tows for automotive application, IOP Conference Series: Materials Science and Engineering, vol. 406, (2018), pp: 012021, DOI: https://doi.org/10.1088/1757-899X/406/1/012021, ISSN 1757-899X (ISI indexed)
T. Ahmed, R. S. Choudhry, Atta Ur Rehman, Hasan Saeed, “A study on pre-damaged stress concentration factor for a composite laminate member with central circular”, Journal of Mechanical Science and Technology, Vol(32) Issue 8, 2018 pp. 3653–8, Springer. doi:https://doi.org/10.1007/s12206-018-0717-4 (ISI indexed)
Muhammad Asif, Muhammad Ali Khan, Sohaib Zia Khan, R. S. Choudhry, Kamran A. Khan, “Identification of an effective non-destructive technique for bond defect determination in laminate composites - a technical review”, Journal of Composite Materials, Sage, Article first published online: March 29, 2018 https://doi.org/10.1177/0021998318766595 (ISI indexed)
A. M. Khan, K. Mahmood, W. H. Syed, R. S Choudhry, S. M. Khan “ Root cause failure analysis of a tracked vehicle balance arm”, Case Studies in Engineering Failure Analysis, Vol. 9 (2017) pp. 112–117 (DOI https://doi.org/10.1016/j.csefa.2017.10.001) (ISI indexed)
Shah, S. Z., Choudhry, R. S., and Khan, L. A., "Challenges in Compression Testing of 3D Angle-Interlocked Woven-Glass Fabric-Reinforced Polymeric Composites," Journal of Testing and Evaluation, Volume 45, Issue 5, September 2017 https://doi.org/10.1520/JTE20160191. ISSN 0090-3973, (ISI indexed)
Zahid Faraz , Syed Waheed ul Haq , Liaqat Ali , Khalid Mahmood , Wasim Akram Tarar, Aamer Ahmed Baqai, Mushtaq Khan, Syed Husain Imran and R. S. Choudhry, Development of a STEP-compliant design and manufacturing framework for discrete sheet-metal bend parts, Proc IMechE Part B: Journal of Engineering Manufacture, pp. 1-15, August 9, 2016 DOI: https://doi.org/10.1177/0954405416661007 (ISI indexed)
R. S. Choudhry, Kamran A. Khan, Sohaib Zia Khan, Muhammad Ali Khan, Abid Hassan, Micromechanical Modeling of 8-Harness Satin Weave Glass Fiber Reinforced Composites, Journal of Composite Materials, Sage Publishers, 2016, DOI: https://doi.org/10.1177/0021998316649782, (ISI indexed)
R.S. Choudhry, Hassan SF, Li S, Day R, Damage in single lap joints of woven fabric reinforced polymeric composites subjected to transverse impact loading, International Journal of Impact Engineering, Vol. 80 (Feb 2015) pp. 76-93, (DOI: https://doi.org/10.1016/j.ijimpeng.2015.02.003) (ISI indexed)
S. Z. H. Shah, R. S. Choudhry, L. A. Khan, Investigation of compressive properties of 3D fiber-reinforced polymeric (FRP) composites through combined end and shear loading, Journal of Mechanical Engineering Research, Vol. 7(4), pp. 34-48, August 2015. doi: https://doi.org/10.5897/JMER2015.0354, ISSN 2141–2383 (Publisher: Academic Journals)
T. Ahmed, R. S. Choudhry, Himayat Ullah, Fahad Hassan, Numerical Modelling of Carbon Fibre Reinforced Polymer Composites for Hole Size Effect, NUST Journal of Engineering Sciences, Vol. 8, No. 1, 2015, pp. 1-9 , ISSN: 2070-9900, http://journals.nust.edu.pk/index.php/njes/article/view/113/73 – Higher Education Commission (HEC) Pakistan, recognized journal.