Integrated Topology Optimization for Construction Equipment Frame

Abstract

one is the simultaneous design of an actuator layout and structural topology of the frame and the other, to consider the manufacturing aspect of the topology optimization result. The embedded actuators in the construction equipment, such as steering cylinders in a wheel loader, transmit external forces to the frame. Because the location of an actuator acts as a loading point in the structure, the optimized structure can be significantly affected by the loading location. Moreover, when the actuator layout is not yet determined at the early concept stage of the frame design, the location of the actuator is allowed to move in a designated design domain. This motivates simultaneous optimization of a loading point and structural topology and this study presents a method to achieve this goal. There have been a few related efforts about the simultaneous optimization of a loading point and structural topology, but the loading point is limited only along a given line or boundary. Even if an optimized layout is found through topology optimization, the actual manufacturing of an optimal structure by welding is a major obstacle because the welding path by the optimization is unrealistic. To overcome this difficulty, we propose a so-called plate-like topology optimization, which extracts the topological layouts of nodal design variables projected on the specified plane along the pre-determined direction. This approach makes the topologically optimized results amenable to the welded structure.

The simultaneous optimization method of a loading point and structural topology and the method to consider the weld manufacturability are implemented by using Matlab and Abaqus. After verification examples are considered, the optimal design of a wheel loader frame is dealt with in order to show the practicality of the proposed method in industrial engineering problems.

The research in this dissertation aims to develop an integrated structural topology optimization method applicable to the design of a construction equipment frame. There are two major design issues existing in the industry