Lightweight Design of a 90M³ Side Dump Trailer Web Flange Subframe Using Manufacturing-Constrained Topology Optimization

Reducing the structural weight of heavy-duty mining trailers is an effective strategy for improving payload capacity, fuel efficiency, and overall operational productivity. Although topology optimization has been widely applied to lightweight structural design, its industrial implementation is often constrained by the generation of complex geometries that are difficult to manufacture using conventional fabrication processes. This study proposes a manufacturing-constrained topology optimization approach for the web flange subframe of a 90 m³ side dump trailer, aiming to achieve weight reduction while preserving structural integrity and fabrication feasibility. A 3D finite element model of the subframe was developed in SolidWorks Simulation using the actual operational loading conditions of the trailer. Baseline static analysis was first performed to identify regions with low material utilization, followed by topology optimization to determine the optimal material distribution. The optimized topology was subsequently reconstructed into a manufacturable design by reducing the flange plate thickness from 12 mm to 10 mm in non-critical regions while maintaining continuous load paths around the axle mounting zones. A secondary finite element analysis was conducted to validate the redesigned structure under identical loading conditions. The optimized design reduced the subframe mass from 1,805.57 kg to 1,613.29 kg, corresponding to a weight reduction of 10.6%. Although the maximum Von Mises stress increased from 26.0 MPa to 46.4 MPa, the redesigned structure maintained a satisfactory factor of safety of 7.54, remaining well below the material yield strength. The proposed approach demonstrates that integrating topology optimization with manufacturing-oriented reconstruction provides a practical and production-ready lightweight design solution for heavy-duty mining trailers, offering improved structural efficiency without compromising safety or manufacturability.