Finite element analysis of thermal-structural coupling in additive manufactured lattice structures for aerospace applications

Project Abstract

This study presents a comprehensive finite element analysis of thermal-structural coupling in additively manufactured lattice structures intended for aerospace applications, focusing on how process-induced defects and temperature-dependent material behavior influence mechanical performance under service-like thermal loads. The work integrates material characterization, lattice topology optimization, and coupled thermo-mechanical simulations to quantify stiffness, strength, and failure mechanisms across a range of operating temperatures and cooling histories typical of aerospace components. A multi-scale modeling framework is developed to bridge the microstructural features inherent to lattice lattices produced by selective laser melting with the macroscopic response of the part, enabling accurate prediction of thermal strains, residual stresses, and deformation patterns that affect load transfer and dynamic performance. First, material properties of the chosen alloy system are experimentally determined, including temperature-dependent Young’s modulus, yield strength, thermal expansion coefficients, and specific heat capacity, alongside the evolution of porosity and microcrack formation under laser heat input. These properties feed into a three-dimensional finite element model that captures lattice unit cell geometries, beam-based continuum representations, and interface conditions between lattice and solid skins. The thermal analysis employs transient heat conduction with boundary conditions representative of flight-surface heating, ambient cooling, and internal cooling channels, coupled to the structural solver to compute thermoelastic response. The coupling mechanism is implemented using a fully coupled field approach to account for the mutual influence of temperature fields and mechanical stresses, including large deformations and potential plasticity at elevated temperatures. Key objectives include evaluating the sensitivity of lattice stiffness and load-bearing capacity to lattice geometry (stretch-duck, body-centered cubic, and gyroid variants), strut thickness, and porosity, as well as assessing how process-induced anisotropy and residual stresses modify buckling and fracture risks under thermal transients. The study investigates damage evolution pathways such as debonding at node joints, microcrack initiation in high-stress regions, and creep effects at high-temperature exposure, offering probabilistic assessments through fracture mechanics-based criteria and Monte Carlo sampling of material and geometric uncertainties. Validation is performed against high-resolution experimental data from thermomechanical tests on additively manufactured lattice coupons and unit cells, including in-situ infrared thermography and digital image correlation to capture temperature distribution and surface deformations. Results indicate that optimized lattice topologies can achieve superior specific strength and thermal resistance while mitigating residual stress accumulation when matched with appropriate build orientation and post-processing. The analysis identifies critical design rules for minimizing thermally induced misalignment and stability issues in aerospace assemblies, such as selecting topology with favorable heat dissipation paths, tailoring strut cross-sections to balance stiffness and ductility, and incorporating sacrificial features to relieve stress concentrations. The research contributes a validated, scalable framework for predicting thermo-structural performance of AM lattice structures under realistic mission profiles, enabling more reliable, weight-efficient aerospace components.

Project Overview

What This Project Is About

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A beginner-friendly overview of how engineers study how heat and structure affect lattice parts made with additive manufacturing, and how this interaction influences performance in aircraft-like applications.

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The Problem It Addresses

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Traditional solid parts can underperform when heat changes cause deformation or stress. Lattice structures are lighter and efficient but their thermal behavior is complex. This project tackles understanding and predicting how temperature changes interact with the structure of 3D-printed lattice joints, aiming to reduce failures and improve safety.

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Objectives of the Project

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1. Explain basic concepts of heat transfer and mechanical stress in lattice materials.
2. Set up a simple computer model to simulate how heat affects a lattice structure.
3. Investigate how different lattice designs respond to temperature changes.
4. Analyze results to identify design choices that minimize deformation.
5. Suggest guidelines for safer, lighter aerospace lattice parts.

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What You Will Do Step by Step

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1) Learn basic terms and tools used in thermal-structural analysis. 2) Build a small lattice model in a user-friendly software. 3) Run simulations to see how heat changes affect shape and stresses. 4) Compare different lattice layouts. 5) Interpret results and discuss practical design tips.

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Expected Outcome

Clear understanding of how temperature changes influence lattice structures, a simple guide for choosing lattice designs that resist deformation, and a demonstration model showing the method developers can extend for more complex parts.