Weight reduction in aerospace equipment is a key approach to enhancing an aircraft's endurance

payload capacity

and overall service performance. Traditional subtractive manufacturing processes struggle to achieve the integrated formation of complex gradient and biomimetic lattice-type lightweight components. Furthermore

existing research on additive manufacturing has largely focused only on component formation quality and static mechanical properties

lacking performance characterization methods covering the entire life cycle of components under extreme conditions such as high temperatures and impact. Consequently

the damage evolution mechanisms of lightweight structures under the coupled effects of extreme environments and manufacturing defects cannot be fully elucidated

which hinders the large-scale implementation of additive-manufactured lightweight components in aerospace engineering.This paper focuses on metal additive manufacturing processes such as laser powder bed fusion (LPBF) and electron beam melting (EBM). By introducing near-field dynamics theory and coupling an adaptive dynamic relaxation algorithm with an LPBF thermal stress analysis model

we have established a full-lifecycle simulation system for aerospace lightweight components under extreme operating conditions;Multiphysics simulation analyses were conducted across six key dimensions: biomimetic gradient lattice configurations

printing anisotropy

high-temperature fatigue at 500°C

dynamic impact energy absorption

thermal residual stresses in the laser melt pool

and full-cycle manufacturing costs.Simulation results indicate that biomimetic gradient lattices can balance structural equivalent stiffness and load-bearing capacity while reducing weight; annealing treatment can significantly mitigate the anisotropy of additive-manufactured components and improve global mechanical uniformity; extreme temperatures of 500°C substantially accelerate fatigue crack propagation rates

and the superposition of surface stress concentrations and melt pool-induced residual tensile stresses further increases the risk of early component failure;under dynamic loads

the gradient lattice can achieve efficient energy dissipation through layer-by-layer buckling and plastic collapse; in small-batch custom production scenarios

additive manufacturing offers significant advantages in terms of unit cost. The coupled simulation system established in this paper quantifies the mechanisms by which biomimetic configurations

heat treatment

process parameters

and extreme service environments influence the mechanical

fatigue

and economic performance of lightweight components

clarifies the mechanisms of full-lifecycle damage evolution in lightweight structures under the coupled effects of high temperature

impact

and manufacturing defects

and provides comprehensive theoretical and simulation support for the topological optimization

process control

and life prediction of load-bearing and impact-resistant lightweight components in aerospace additive manufacturing.