Topology optimization for weight reduction and geometric refinement of a mounted mouldboard plough structure

Abstract

Topology optimization is one of the structural optimization methods whose goal is to find the optimal distribution of materials within the design domain. Various approaches have been developed for topology optimization, including methods based on material density distribution and those utilizing level set functions. In one approach, known as the Solid Isotropic Material with Penalization method (SIMP), the density assigned to each element in the finite element model indicates the presence or absence of material within that element. During the optimization process, the density distribution vector is iteratively updated based on the objective function and imposed constraints, and finally, the optimal shape for the desired structure can be obtained. Moreover, the structure must be able to maintain functional conditions. In this study, topology optimization was performed on a mounted mouldboard plough structure. Two problems are presented. Problem 1: Weight-constrained Von-Mises stress minimization and Problem 2: Volume-constrained strain-energy (≡compliance) minimization. For this purpose, the interaction of a complete model of a three-bottom mouldboard plough with soil was simulated in Abaqus software to estimate the resistance forces applied to the plough. Then, static analysis of the plough structure was performed, and the stress concentration on different chassis locations was determined. In the next step, topology optimization of the plough structure was investigated in two types of objective functions (Von-Mises stress and strain energy) by applying boundary conditions and different constraints, and consequently the optimal geometry and weight in each stage were extracted. The results showed that it is possible to reduce the weight of the plough structure by up to 18% in the first topology optimization (weight and stress reduction) and the possibility of reducing the weight by up to 22% in the second topology optimization (reducing the weight and strain energy) while maintaining the functional condition of the plough structure.