Principal Stress Engineer – Composite Structures and Defense Hardware

Principal Stress Engineer – Composite Structures and Defense Hardware

El Segundo, CA | On‑site

A rapidly expanding defense‑focused startup is seeking a Principal Stress Engineer to establish and lead structural analysis for breakthrough composite technologies. The organization is developing high‑performance manufacturing methods for complex composite parts used in aerospace, defense, and energy applications. With strong customer traction and an aggressive roadmap, the company is building a world‑class engineering team to validate and optimize its novel material systems.

In this role you will build advanced FEA frameworks, interpret material data, guide design decisions, and validate performance through rigorous testing, connecting simulation, characterization, and real‑world conditions.

We are an emerging engineering startup developing a proprietary manufacturing approach for fiber‑reinforced composites that dramatically increases production speed and lowers cost while maintaining exceptional structural performance. Our technology supports a wide range of high‑value defense, aerospace, and industrial applications. With multiple programs already underway, we are expanding our technical organization to deepen analytical capabilities, refine material behavior models, and enable robust product development at scale.

• Create, validate, and maintain the company’s initial finite element modeling framework for new composite materials and structural applications.
• Partner with materials engineers and technicians to gather input data, characterize material response, and ensure accurate simulation parameters.
• Design and coordinate mechanical testing for coupons, representative geometries, and full components to connect simulation results with real‑world behavior.
• Analyze structural response using FEA and use results to influence design choices, process refinement, and material selection.
• Develop internal standards, methods, templates, and analytical tools to support scalable composite stress analysis.
• Conduct failure investigations, evaluate root‑cause scenarios, and document findings to improve designs and manufacturing consistency.
• Manage, mentor, and collaborate with engineers and technicians involved in analysis, testing, and development activities.
• Occasionally engage with customers to discuss requirements, share data, and present results or simulations.

• 5+ years of experience performing stress analysis for composite materials or structural composite components.
• Background developing and refining FEA models for novel materials or nontraditional composite architectures.
• Ability to design, configure, and scale a complete FEA analysis system including software selection, structural setup, validation approaches, and parameter definition.
• Experience using FEA to optimize weight, geometry, and structural integrity of composite parts.
• Ability to design and interpret mechanical tests for coupons, sub‑elements, and finished geometries.
• Familiarity with failure mode investigation, structural test correlation, and root‑cause analysis.
• Proficiency in CAD modeling with experience creating part and assembly drawings using GD&T.
• Strong communication and collaboration skills, with the ability to work effectively across materials, manufacturing, and design teams.
• Bachelor’s, Master’s, or PhD in Mechanical Engineering, Aerospace Engineering, Materials Engineering, or a related discipline.

• 10+ years working in composite stress analysis.
• Exposure to thermal or coupled thermal‑structural simulations.
• Experience supporting composite manufacturing environments.
• Familiarity with Onshape or similar CAD platforms.
• Background in defense, aerospace, or other high‑reliability industries.

• Opportunity to define and scale the structural analysis discipline within a rapidly growing composite technology company.
• Pathways to leadership roles as analytical capabilities expand.
• Influence key decisions across materials, simulation, and design methodologies.
• Ability to develop new analysis techniques, support intellectual property creation, and introduce advanced simulation capabilities.
• Stock options.
• 401(k) with employer match.
• Medical, dental, and vision benefits.

$180,000 - $230,000 (annual)

Mid‑Senior level

Full‑time

Engineering and Information Technology;
Industries:
Defense and Space Manufacturing, Space Research and Technology, and Manufacturing