Staff Mechanical Design Engineer, Battery Analysis Rivian - 2.7 Tustin, CA Job Details Full-time 22 hours ago Qualifications Solid mechanics FEA Full Job Description Rivian is seeking a Sr. Staff Mechanical Design Engineer, Battery Analysis to join the Battery Analysis team within Energy Storage Systems. In this role, you will provide technical leadership for dynamic deformation and thermal-structural CAE of battery packs, modules, and related components. You will use explicit finite-element simulation, thermal-structural analysis, engineering judgment, and test correlation to inform design direction, evaluate crash, impact, durability, and environmental performance, and improve design validation. The ideal candidate combines deep expertise in dynamic deformation (damage) and thermal-structural analysis developing analysis methods, material models, load profiles, and engineering recommendations. You will work across Product Design, Battery Systems, Test, Reliability, Manufacturing, and program teams to translate complex analysis into clear decisions and robust battery designs. Lead dynamic-deformation and thermal-structural CAE for battery pack and module designs across development and validation phases. Design and optimize multi-material vertical stack-ups by balancing high-yield protective layers (such as high-strength steel or composite skid plates) to distribute concentrated impact loads with tailored, energy-absorbing crush buffers (like foam, elastomeric pads, or structural potting) to dissipate peak dynamic forces, control localized intrusion, and prevent critical mechanical stress transfer to internal battery components during severe top or ground strike events. Develop and improve explicit finite-element models for crash, impact, crush, drop, abuse and other transient load cases. Develop and improve FE models for thermal-structural response, including thermal expansion, coupled temperature-mechanical loading and durability-related assessments. Develop and execute Design of Experiments (DOE) to establish structural and thermal sensitivity maps, quantify parameter trade-offs, and define upper- and lower-bound "bookend" performance envelopes that guide early-stage design direction and accelerateprogram decision-making. Execute simulation studies that support design tradeoffs, risk reduction, design verification, and production readiness. Develop and maintain material cards, constitutive models, contact definitions, failure criteria, boundary conditions, mesh strategies, and solution controls appropriate to explicit and thermal-structural analysis. Generate and apply load profiles, including crash and impact pulses, vibration, shock, thermal expansion, durability, and manufacturing-related loads. Evaluate stresses, strains, deformation, energy absorption, intrusion, fatigue, interface loads, and failure risks in structures, potting, adhesives, busbars, current collector assemblies, and related components. Correlate CAE predictions with component, module, pack, and vehicle-level test data; investigate discrepancies and improve model fidelity. Define assumptions, sensitivities, acceptance criteria, and confidence levels for analysis results. Communicate technical findings through clear reports, data packages, reviews, and recommendations for engineering and program stakeholders. Partner with design engineers to identify design, material, manufacturability, and validation risks early enough to influence the product. Support root-cause investigations and corrective actions for structural, thermal-structural, durability, and manufacturing concerns. Establish and maintain reusable analysis workflows, templates, material databases, profile-generation methods, and documentation. Mentor engineers and contribute to technical standards, best practices, and the long-term capability of the Battery Analysis team. Bachelor's degree in Mechanical Engineering, Aerospace Engineering, Civil or Structural Engineering, Materials Engineering, or a related field. Significant professional experience applying CAE to mechanical, structural, thermal-structural, or durability problems in complex products. Strong understanding of mechanics of materials, finite-element methods, nonlinear behavior, thermal expansion, contact, material behavior, energy absorption, and failure modes. Demonstrated hands-on experience using LS-DYNA (preferred) for explicit dynamic analysis, including model setup, contact, material and failure definitions, timestep or mass-scaling considerations, solver controls, and post-processing. Demonstrated hands-on experience using OptiStruct (preferred) for thermal-structural and structural analysis, including thermal loading, material and boundary-condition definition, modal or static response, and interpretation of results.

Thermal-to-Structural Data Mapping & Mesh Interpolation:

Hands-on experience mapping 3D non-uniform temperature fields from thermal solver grids (e.g., Fluent, STAR-CCM+) onto non-conformal structural FEA meshes (e.g., OptiStruct or LS-DYNA) using spatial spatial-interpolation methods Experience modeling for assemblies containing metals, polymers, adhesives, foams,potting materials, or similar interfaces. Experience developing or applying crash, impact, crush, drop, vibration, shock, durability, thermal, or manufacturing load cases. Experience correlating simulation results with physical test data and using the findings to improve models or design decisions. Working knowledge of engineering drawings, geometric dimensioning and tolerancing, material properties, and design-for-manufacturing considerations. Ability to communicate complex technical topics clearly to both technical and non-technical audiences. Ability to execute multiple projects, make evidence-based recommendations, and deliver against program timing. Demonstrated ability to work effectively with cross-functional teams and provide technical direction without relying on formal authority.

Preferred Qualifications:

Master's or Ph.D. in Mechanical Engineering, Aerospace Engineering, Structural Engineering, Materials Engineering, or a related field. Experience with battery packs, modules, cells, current collector assemblies, busbars, potting, adhesives, thermal management, or high-voltage energy-storage systems. Experience with thermal-mechanical or coupled multiphysics analysis. Experience with fatigue, random vibration, shock response, response-spectrum methods, PSD development, or damage calculations. Experience with crash, impact, large-deformation, vehicle bottom structure protection like skid plates and dynamic intrusion of composite materials. Experience creating automated workflows, post-processing tools, or engineering data pipelines. Experience executing multi-disciplinary design optimization (MDO) using tools like LS-OPT, HEEDS, or OptiStruct to concurrently balance structural mass, dynamic energy absorption, and thermal deformation across complex, multi-material battery assemblies. Experience developing material models or material cards from coupon, component, or supplier data. Advanced experience with LS-DYNA and OptiStruct; proficiency with HyperMesh, Ansa or comparable pre- and post-processing tools. Experience with Abaqus, ANSYS, NCode, MATLAB, Python, or comparable CAE and data-analysis tools. Experience leading technical reviews, mentoring engineers, and establishing analysis standards across programs.