I am a research associate in nonlinear structures at the University of Bristol and specialise in lightweight design of aerospace components. This means I try to make wings, fuselages, rocket shells, etc. as light as possible without them breaking, snapping, crushing … basically failing in service before they are meant to.
Why nonlinear? Because designing lightweight structures often entails optimising one aspect of the structure; the parameter that most influences the design.
Unfortunately, optimising for one parameter can make the structure quite fragile, and when the structure exceeds its design loading, failure can be sudden and dramatic. The ensuing large deformations in these collapse events can only be modelled accurately when nonlinearities are taken into account.
On the other hand, there are cases where we want structures to reliably undergo large deformations. For example, we can design structures that snap between two stable states and this can be used to optimise the performance under changing loading conditions. This approach is known as shape morphing and is generally how nature goes about optimising for changing environments.
You can find my contact details and a list of select publications below. To get in touch, please leave a comment and I will get back to you ASAP.
Rainer Groh, PhD MEng
Postdoctoral Research Associate in Nonlinear Structures
Bristol Composites Institute (ACCIS)
Department of Aerospace Engineering, University of Bristol
Queen’s Building, University Walk, Bristol, BS8 1TR, UK
RMJ Groh (2015). Non-classical effects in straight-fibre and tow-steered composite beams and plates. University of Bristol. Bristol, UK.
Advanced Materials & Structures 3 – Bending and Buckling of Plates, Department of Aerospace Engineering, University of Bristol.
G Arena, RMJ Groh, A Brinkmeyer, R Theunissen, PM Weaver, A Pirrera (2017). Adaptive compliant structures for flow regulation. Proceedings of the Royal Society A, 473:20170334. DOI: 10.1098/rspa.2017.0334.
RMJ Groh, A Tessler (2017). Computationally efficient beam elements for accurate stresses in sandwich laminates and laminated composites with delaminations. Computer Methods in Applied Mechanics and Engineering, 320, (pp. 369–395). DOI: 10.1016/j.cma.2017.03.035.
C Thurnherr, RMJ Groh, P Ermanni, PM Weaver (2017). Investigation of failure initiation in curved composite laminates using a higher-order beam model. Composite Structures, 168, (pp. 143–152). DOI: 10.1016/j.compstruct.2017.02.010.
A Madeo, RMJ Groh, G Zucco, PM Weaver, G Zagari, R Zinno (2017). Post-buckling analysis of variable-angle tow composite plates using Koiter’s approach and the finite element method. Thin-Walled Structures, 110, (pp. 1-13). DOI: 10.1016/j.tws.2016.10.012.
RMJ Groh, PM Weaver (2016). Deleterious localized stress fields: the effects of boundaries and stiffness tailoring in anisotropic laminated plates. Proceedings of the Royal Society A, 472:20160391. DOI: 10.1098/rspa.2016.0391.
C Thurnherr, RMJ Groh, P Ermanni, PM Weaver (2016). Higher-order beam model for stress predictions in curved beams made from anisotropic materials. International Journal of Solids and Structures, 97–98, (pp. 16–28). DOI: 10.1016/j.ijsolstr.2016.08.004.
G Zucco, RMJ Groh, A Madeo, PM Weaver (2016). Mixed shell element for static and buckling analysis of variable angle tow composite plates. Composite Structures, 152, (pp. 324–338). DOI: 10.1016/j.compstruct.2016.05.030.
RMJ Groh, PM Weaver (2016). A computationally efficient 2D model for inherently equilibrated 3D stress predictions in heterogeneous laminated plates. Part II: Model validation. Composite Structures, 156, (pp. 186-217). DOI: 10.1016/j.compstruct.2015.11.077.
RMJ Groh, PM Weaver (2016). A computationally efficient 2D model for inherently equilibrated 3D stress predictions in heterogeneous laminated plates. Part I: Model formulation. Composite Structures, 156, (pp. 171-185). DOI: 10.1016/j.compstruct.2015.11.078.
RMJ Groh, PM Weaver, A Tessler (2015). Application of the Refined Zigzag Theory to the modeling of delaminations in laminated composites. NASA/TM-2015-218808.
RMJ Groh, PM Weaver (2015). On displacement-based and mixed-variational equivalent single layer theories for modelling highly heterogeneous laminated beams. International Journal of Solids and Structures, 59, (pp. 147–170). DOI: 10.1016/j.ijsolstr.2015.01.020.
RMJ Groh, PM Weaver (2015). Static inconsistencies in certain axiomatic higher-order shear deformation theories for beams, plates and shells. Composite Structures, 120, (pp. 231–245). DOI: 10.1016/j.compstruct.2014.10.006.
RMJ Groh, PM Weaver (2014). Buckling analysis of variable angle tow, variable thickness panels with transverse shear effects. Composite Structures, 107, (pp. 482–493). DOI: 10.1016/j.compstruct.2013.08.025.
RMJ Groh, PM Weaver, S White, G Raju, Z Wu. (2013). A 2D equivalent single-layer formulation for the effect of transverse shear on laminated plates with curvilinear fibres. Composite Structures, 100, (pp. 464–478). DOI: 10.1016/j.compstruct.2013.01.014.
RMJ Groh, A Pirrera (2017). Exploring islands of stability in the design space of cylindrical shell structures. Shell Structures: Theory and Applications Volume 4, Routledge, pp. 223-226.
Conference Papers and Presentations
RMJ Groh, A Pirrera (2017). A general computational framework for designing morphing structures. IN: Proceedings of the 21st International Conference on Composite Materials. Xi’an, China.
RMJ Groh, A Pirrera (2017). Numerical continuation—a robust approach for nonlinear stability analysis of composite shell structures. 3rd International Conference on Mechanics of Composites. University of Bologna, Italy.
G Arena, RMJ Groh, R Theunissen, PM Weaver, A Pirrera (2016). Adaptive Nonlinear Structures for Flow Regulation: Modelling Fluid-Structure Interactions with Coupled Eulerian-Lagrangian Meshes. IN: 2016 SIMULIA UK Regional User Meeting. Manchester, UK.
A Madeo, G Zagari, G Zucco, RMJ Groh, PM Weaver, R Zinno (2016). Koiter asymptotic analysis of Variable Angle Tow composite plates. ECCOMAS Congress 2016. Crete, Greece.
RMJ Groh, PM Weaver (2015). A mixed-variational, higher-order zig-zag theory for highly heterogeneous layered structures. 18th International Conference on Composite Structures. Lisbon, Portugal.
RMJ Groh, PM Weaver (2015). Full-field stress tailoring of composite laminates. IN: Proceedings of the 20th International Conference on Composite Materials. Copenhagen, Denmark.
RMJ Groh, PM Weaver (2015). Mass Optimization of Variable Angle Tow, Variable Thickness Panels with Static Failure and Buckling Constraints. IN: Proceedings of AIAA SciTech: 56th AIAA/ASME/ASCE/AHS/ASC Structures, structural dynamics and materials conference. Kissimmee, FL, USA.
RMJ Groh, PM Weaver (2014). Post-buckling analysis of variable angle, variable thickness panels manufactured by Continuous Tow Shearing. 1st International Conference on Mechanics of Composites. Stony Brook University, USA.
RMJ Groh, PM Weaver (2013). Buckling analysis of variable angle tow, variable thickness panels with transverse shear effects. IN: Proceedings of the International Conference on Composite Materials 19. Montreal, Canada.
RMJ Groh, PM Weaver (2013). Buckling analysis of variable angle tow, variable thickness panelswith transverse shear effects. 17th International Conference on Composite Structures. Porto, Portugal.
Collier Research HyperSizer/AIAA Structures Best Paper Award at AIAA SciTech: 56th AIAA/ASME/ASCE/AHS/ASC Structures, structural dynamics and materials conference. Kissimmee, FL, USA.
Ian Marshall’s Award for Best Student Paper at the 17th International Conference on Composite Structures, Porto, 2013.