Services
FIve disciplines — one integrated engineering loop
01 | LIGHTWEIGHT STRUCTURES
PRIMARY OFFER
Structural optimisation for minimum weight
Full-loop design and analysis for structures where every gram saved translates directly into performance, range, or payload capacity. Geometry, material selection, FEM validation, and design iteration run in parallel until mass targets are met without compromising strength, stiffness, or fatigue life.
Optimisation is approached both top-down and bottom-up: topological optimisation strips non-load-bearing material from an existing design, while parametric FEM sweeps explore entire design spaces — geometry, layup, reinforcement pattern, wall thickness — to identify configurations no single hand calculation would find. Both static and dynamic requirements are treated as first-class constraints, not afterthoughts: buckling, modal response, and fatigue life are verified alongside mass and stress targets from the first iteration, not bolted on at the end.
Manufacturing constraints are embedded from day one — not added at the end. For composite structures this means laminate buildability, ply continuity around corners, tool access, and bonding vs. fastening trade-offs. For metallic structures it means weldability, standard profile availability, machining tolerances, and fabrication sequencing. For injection-moulded parts it means wall thickness uniformity, draft angles, and rib design within tool constraints. Every optimised design is a design that can actually be built.
Recent applications
Steel chassis mass reduction (Switzerland) — comparative FEM of four structural variants for a 6.2 m steel chassis under four load cases including eccentric pallet loading and lateral forces. Mass reduced by 44% (1091 kg → 609 kg), maximum stress 134 MPa, safety factor 2.6 on S355 yield strength.
Stratospheric capsule pressurised CFRP shell (Spain) — structural sizing of a pressurised CFRP shell for a near-space passenger capsule. T800S/3900-2 prepreg UD, laminate sized for 0.1 MPa internal pressure (SF 24.8), out-of-autoclave + AFP manufacturing strategy (void content < 2%), phased certification plan including CAI, fatigue, and burst pressure testing.
Guitar case mass reduction — DFM for injection moulding (USA) — structural redesign of an injection-moulded ASA guitar case to reduce mass from 9 lbs to 6.7 lbs (26%) while maintaining structural integrity under buckling and material strength requirements. Redesigned internal rib system on the side walls and belly panels to improve rigidity and compensate for reduced wall thickness, balanced against injection moulding process constraints (draft angles, wall uniformity, tool complexity).
02 | COMPOSITE & HYBRID STRUCTURES
PRIMARY OFFER
PRIMARY OFFER
Composite and hybrid structure analysis
Laminate design, progressive damage modelling, and failure prediction for fibre-reinforced polymers — with stress-based and strain-based criteria applied at the correct scale. Doctoral-level expertise in compression failure mechanics (CNRS—LMA / DGA) combined with experience on major aerospace and defence programmes. Carbon, glass, flax, and hybrid metal-composite assemblies. From coupon-level characterisation to full component FEM.
Composite design at ANDEXTRA is inseparable from manufacturing knowledge. Laminate architectures are defined with process constraints in mind: TFP fibre placement for complex curves, OOA and autoclave trade-offs, half-shell bonding strategies to eliminate fasteners, ply drop management, and interface design between composite skins and metallic inserts. The result is a design that performs insimulation and survives production.
Recent applications
AUV pressure hull (Poland) — zone-partitioned FEM optimisation of a CFRP/PVC sandwich pressure hull across 9 structural zones. Shows sandwich construction and multi-zone design, which the current two examples don't cover.
Industrial robotics CFRP component (France) — TFP-optimised laminate, half-shell bonding strategy, adhesive shear verification, modal analysis. Strongest DFM-for-composites story in your portfolio — bonding vs. rivets, manufacturing-driven laminate architecture.
Launch vehicle fairing material study (France) — parametric comparison of monolithic vs. sandwich vs. stiffened architectures. Shows comparative material selection methodology, not just single-design optimisation.
03 | DIGITAL TWINS & CHARACTERISATION
From test data to calibrated models — digital twins and experimental characterisation
Structural simulation is only as reliable as the material model behind it. When standard handbook values are insufficient — or when a structure has been tested and the model must be made to match — ANDEXTRA builds and calibrates FEM models directly from experimental evidence.
The core methodology is inverse identification: strain fields measured by 3D Digital Image Correlation (DIC) or load-displacement curves from mechanical tests are used as targets, and a Python-driven optimisation loop identifies the elastic, damage, or plasticity parameters that reproduce the observed behaviour. On the experimental side, ANDEXTRA designs the test programme itself: specimen geometry, instrumentation strategy, loading protocol, and data acquisition.
Recent applications
Steel interlocking connection — nonlinear FEM and test correlation (research project, UK) — full nonlinear FEM of a steel beam-to-column interlocking connection including 18 M12 Grade 8.8 bolts with 35 kN preload, frictional contact, and geometric nonlinearity. Force-strain correlation against physical test results within 8% deviation across all loading stages, capturing elastic, transition, and progressive yielding phases matching the experimental failure load.
GFRP spacer tube — material identification and long-term creep (construction products manufacturer, UK) — three-point bending FEM used to identify axial modulus and failure strain from physical test data on three pultruded tube geometries. Identified properties applied to a cantilever spacer model under sustained load across 150+ parametric simulations, with long-term creep behaviour assessed per Eurocomp knock-down factors to guide final sizing.
04 | CFD AND THERMAL ANALYSIS
CFD, thermal and polymer structural analysis
Internal flow simulation for rotating machinery: stage performance maps, pressure recovery, eficiency at design and off-design operating points, and loss breakdown by component. Rotor-stator interaction modelled with MRF or sliding mesh approaches depending on accuracy requirements.
Thermal analysis of structures and electronic assemblies: conjugate heat transfer simulation to predict temperature fields in heat sinks, cold plates, PCB substrates, and electronic packages under operational and peak load conditions. Coupled thermo-mechanical FEM to quantify thermally induced deformation — critical for optical, precision, and power electronics applications.
Structural simulation of polymer and plastic components: nonlinear FEM for injection-moulded housings, polymer brackets, and multi-material assemblies. Creep and relaxation under sustained loads, temperature-dependent stiffness, and failure prediction for thermoplastic and thermoset parts.
Particularly relevant for consumer electronics, medical devices, and industrial enclosures where metallic FEM assumptions do not apply.
Python post-processing pipelines for margin extraction, hotspot identification, and parametric design sweeps across all simulation types.
Recent applications
Multilayer PCB thermo-mechanical analysis (optical sensing systems, Austria) — complete reconstruction of a 10-layer multilayer PCB from Gerber files into a parametric CAD model (400 MB STEP), including all copper layers, dielectric prepreg, vias, and pins as solid bodies. Homogenised orthotropic material properties (Exx = Eyy = 28.7 GPa; Ezz = 5.5 GPa) derived from the detailed model by simulation of a 25°C thermal expansion cycle. Full thermo-mechanical FEM of the PCB + sensor + chip assembly under 2.23 W sensor heat load: equilibrium temperature rise of 27.4°C above board temperature, maximum structural deformation of 9.2 µm. Results validated against manufacturer thermal data, with deformations confirmed within optical alignment tolerances.
Aluminium PCB thermal analysis for high-power LED lighting (automotive lighting, Spain) — thermal FEM of an aluminium-substrate PCB assembly. Temperature field prediction under operational heat flux, hotspot identification, and margin analysis against component thermal limits.
Battery pack cold plate — conjugate heat transfer (EV powertrain developer, France) — conjugate heat transfer simulation of a 120S 1P lithium-ion battery pack with serpentine cold plate cooling under 250 kW PowerShot discharge cycles. Temperature field extraction, cell-level margin analysis, and Python post-processing pipeline for parametric cold plate design sweeps.
05 | DRONE AND AUTONOMOUS VEHICLE DESIGN
Drone and autonomous vehicle structural design
Integrated structural design for unmanned aerial and ground vehicles — from concept geometry to flight-ready or field-ready structural validation. Airframe layout, load case definition, material selection, and FEM-driven iteration to achieve minimum weight with maximum structural efficiency.
A key differentiator is the composite-native design approach: airframe architectures are conceived for the material from the outset, not adapted from metallic frameworks. This means flat CNC-cuttable plate geometries, adhesive joints loaded in shear, standard CFRP tube sizes, and assembly sequences requiring no specialist tooling or autoclave. For metallic UGV structures, DFM means weldability, standard steel sections, and machinability of critical interfaces. For aerial platforms, aerodynamic load estimation is integrated into the structural loop, ensuring the structure is sized for realistic in-flight conditions.
Recent applications
CFRP quadcopter frame — parametric optimisation study (DARPA challenge) — fully parametric FEM model of a quadcopter airframe combining 20 mm OD CFRP tubes and composite central body plates. Parameters swept simultaneously: arm wall thickness, arm length, central hole diameter, laminate layup (quasi-isotropic baseline 0/45/−45/90, UD CFRP standard and high-modulus E11 = 110-300 GPa), and bracing reinforcement count and position. For each configuration, four outputs extracted and combined into a weighted effectiveness coefficient: total mass, first three natural frequencies, maximum tip displacement under rotor thrust, and safety factor of the most stressed component. Optimal configuration identified by ranking across the full parametric space — framework adjustable to client priorities.
Tactical breacher drone — structural design and impact FEM — full structural design of a compact quadrotor in inverted pusher configuration for indoor and urban operations. Asymmetric sandwich structure with 6 mm CFRP top plate (primary structural element and motor mount) and 3 mm CFRP bottom plate. Vibration-isolated mission deck (200 × 60 mm, M-LOK grid, silicone bobbin isolation). FEM impact study at three severity levels: 500 g (elastic, frame survives at 18 m/s), 2000 g (localised delamination risk at arm joints), and 3500 g (non-survivable, crumple zone strategy recommended). NDAA-compliant component selection throughout.