Senior Stress & Thermomechanical FEA Engineer - Propulsion Battery System (all genders)

About the role

Your Mission: As Senior Stress & Thermomechanical FEA Engineer – Propulsion Battery System (all genders) you will join VÆRIDION’s Technology division within the Mechanical Design & Integration team and lead the structural, stress, and thermomechanical finite element analysis (FEA) of the propulsion battery system for VÆRIDION’s CS-23 all-electric aircraft. You will own the computational modelling of battery packs, power distribution units (PDUs), and their internal hardware, predicting how every component behaves under nominal and emergency conditions – including thermal runaway, the DO-160 environmental qualification conditions applied to the pack and PDU as airborne equipment (temperature and altitude, temperature variation, humidity, operational shocks and crash safety, and vibration), flight loads, and durability over service life. Your analysis will provide engineering evidence that the propulsion battery system is structurally robust, thermally safe, and certifiable. Within the Mechanical Design & Integration team, you will collaborate with Mechanical Design, Materials & Processes, Test, HV Electrical Systems, Airborne Electronics, Thermal Systems, Aircraft Structures, Certification, Safety, and Quality teams to define analysis methods, apply the material property allowable required for your analyses, and substantiate the qualification of the propulsion battery pack and PDU. You will be the structural and thermomechanical analysis authority for the propulsion battery system, responsible for checking and releasing design against the applicable stress and thermomechanical requirements. Your work will directly contribute to the propulsion battery system that underpins VÆRIDION’s mission to bring electric flight to regional aviation. Your Day-to-Day: Lead the structural, stress, and thermomechanical FEA of propulsion battery packs, PDUs, and their internal components, predicting how they behave under nominal operation and emergency conditions – including thermal runaway, the DO-160 environmental qualification conditions, and flight and inertial loads. Perform room-temperature and elevated-temperature analysis of composites (including sandwich structures), metals, adhesives, and mechanical fasteners, capturing temperature-dependent material behaviour. Build and correlate nonlinear models covering material, geometric, and contact nonlinearity – including cohesive-zone and VCCT delamination, composite progressive failure and damage propagation, metal plasticity and rate-dependent behaviour, crushable foam plasticity and densification, large-deformation and post-buckling response, and frictional contact with bolt pretension, including bearing behaviour at fastener holes (bearing yield, hole elongation, and bearing–bypass interaction). Model the hyper-elastic and viscoelastic behaviour of potting compounds, gap fillers, foams, gaskets, seals, and thermal interface materials to predict contact pressure and interface integrity across the life of the pack. Perform durability and life analysis across the differing service lives of components within the system, covering vibration-induced high-cycle fatigue (DO-160 random and sine sweep), low-cycle fatigue from ground–air–ground and charge/discharge thermal cycling, and fatigue of bonded joints, fasteners, busbars, and interconnects. Assess creep and stress relaxation of seals, adhesives, polymers, potting compounds, and thermal interface materials at elevated temperature, including loss of contact pressure across a pack replacement interval. Analyse thermal runaway response as a coupled thermomechanical event – pressure loads, direct impingement flow, ejecta, and heat transfer to surrounding structure and systems – working closely with the Thermal Systems team on thermal runaway CFD modelling and the resulting heat transfer boundary conditions, in support of containment and continued safe flight and landing. Apply static, fatigue, and creep material property allowable (room and elevated temperature) in the substantiation of the propulsion battery pack and PDU, working to established methodologies such as CMH-17 for composites and MMPDS for metallics, and specify the allowable, material data, and test conditions required from the Materials & Processes and Test teams. Automate and script analysis workflows – model generation, parametric studies, load case sweeps, and post-processing – using Python for Abaqus scripting, and develop closed-form and lower-order analysis methods in Python or MATLAB to size hardware quickly and to verify finite element results. Interface closely with the Mechanical Design, Materials & Processes, and Airborne Electronics teams to translate analysis results into design improvements and robust, certifiable hardware. Check and release design against the applicable stress and thermomechanical requirements, providing the stress sign-off for propulsion battery pack and PDU hardware releases. Define modelling standards, assumptions, load cases, and acceptance criteria, and maintain configuration-controlled analysis models and inputs. Support test planning and post-test correlation of FEA models against coupon, component, and full-scale test data. Author and release certification documentation, including analysis reports and means-of-compliance evidence for structural, environmental, and thermal runaway requirements. Your Profile: Bachelor’s or Master’s degree in Mechanical Engineering, Aerospace Engineering, Structural/Computational Mechanics, or a related field; a PhD in a relevant area is beneficial. 5+ years of experience in structural/stress and thermomechanical FEA, preferably in aerospace, automotive, battery systems, or other high-performance engineering environments. Experience taking analytical responsibility for hardware, including checking the work of others and providing stress sign-off or equivalent release approval within a configuration-controlled environment, is desirable. Strong command of nonlinear FEA across material, geometric, and contact nonlinearity, with depth in several of the following: cohesive-zone modeling with traction–separation, composite progressive failure (e.g., Hashin/Puck), metal plasticity and viscoplasticity, hyperelastic and viscoelastic materials, crushable foam plasticity, large-deformation and buckling, and frictional contact with pretension, including fastener bearing and bearing–bypass analysis. Experience with room-temperature and elevated-temperature modeling of composites (including sandwich structures), metals, adhesives, and mechanical fasteners, covering temperature-dependent material behavior. Experience in fatigue and damage-tolerance analysis (S–N/ε–N methods, cumulative damage, random-vibration/PSD fatigue) and in creep and stress-relaxation behavior of adhesives and polymers at elevated temperature. Experience with explicit dynamics and impact/blast-type events (e.g., burst-disk actuation, vent impingement, ejecta and debris containment) is desirable. Proficiency with FEA software, ideally Abaqus; experience with tools such as Ansys (Mechanical/LS-DYNA), MSC/NX Nastran, Altair (HyperMesh/OptiStruct/Radioss), or COMSOL is beneficial. Experience implementing user-defined material models and subroutines in Abaqus (UMAT/VUMAT/UMATHT), including the ability to write and debug Fortran, is desirable. Proficiency in scripting: Python for Abaqus automation and post-processing, and Python or MATLAB for closed-form and lower-order analysis methods used to size hardware and verify finite element results. Proficiency with 3D CAD, ideally SolidWorks or CATIA, is desirable; experience with Siemens NX is beneficial. Experience applying static, fatigue, and creep material property allowables to the substantiation of structural hardware, including familiarity with CMH-17 and MMPDS methodologies or equivalent, and with A-/B-basis statistical allowables. Familiarity with aerospace environmental and structural requirements, in particular DO-160 environmental conditions and CS-23 structural substantiation, is desirable. Working knowledge of propulsion battery thermal runaway means of compliance, including DO-311A and the ANAC–EASA–FAA–TCCA harmonized thermal runaway white paper for propulsion batteries, is beneficial. Familiarity with development assurance and safety processes (e.g., ARP4754A/B, ARP4761/4761A, and ASTM F3230 for small aircraft) is beneficial. Experience with battery systems or electric propulsion systems is beneficial. Strong problem-solving skills, technical curiosity, and attention to detail. Strong written and verbal communication skills and the ability to work effectively in a multidisciplinary engineering environment. Fluent English language skills are essential; German language skills are beneficial. We recognize that women and other under-represented groups are often overlooked in our industry. If you’re excited about this role but don’t meet every listed qualification, we still encourage you to apply. Talent and potential can’t always be captured in a checklist. Why us? Be part of an ambitious team determined to shape the future of aviation. We are an in-office company, but we value flexibility and trust employees to manage their schedules responsibly. This may include occasional remote work or adjusting hours to accommodate personal commitments. Subsidized EGYM Wellpass membership: your (mental) health is important for us. Enjoy a subsidized lunch with a 5€ company contribution per meal on office days. Become a part of our success with virtual stock options. Choose the option that suits your needs: either a free charging station for your electric car or a public transport job ticket as part of the Deutschlandticket. Lease a high-quality bicycle or e-bike through our JobRad program and benefit from tax advantages. Whether for your daily commute or personal use, enjoy more mobility and sustainability. Pension scheme to support your long-term financial security. Work in one of our offices in Munich or Delft. Enjoy the modern Balan Campus in Munich or work inside the aerospace ecosystem at TU Delft. Boost your professional as well as personal growth executing your own ideas and independent projects. Join our internal social events and retreats (e.g. cooking, game nights, sports VÆRIDION was founded in 2021 to transform regional air travel with the Microliner, a 100% electric commercial aircraft. By delivering the most energy-efficient aircraft, we are building the future where clean, safe, and affordable electric aviation seamlessly connects people and businesses. We’re bringing together the brightest minds in aerospace, automotive engineering, and business to disrupt the aviation industry.