Influence of Variable Support Conditions on Topology Optimization of Load-Carrying Parts

Abstract

The paper addresses the importance of proper modeling of boundary conditions in preparing a FEA model for topology optimization of load-carrying structural parts. More specifically, the focus is on possible variations of support conditions during the service life of a structural part. Such variations emerge from various reasons, for example, from a fixing screw becoming loose. Since such variations are not deterministic and may cause the structural part to operate within a wide range of various conditions, this paper aims to improve the insight into this problem and to suggest a way to mitigate it. For this purpose, a bracket intended to carry a hydraulic motor is used as a test example and the topology of its design is optimized under various support conditions. The results are then analyzed in order to evaluate the consequences, caused by variations of the supports. Furthermore, a novel optimization procedure scheme is proposed based on selective load cases activity. This procedure aims to reduce the computational effort that may otherwise increase by an order of magnitude due to addition of all possible support variations. It is shown that adequate preparation of load cases that include all possible support conditions is of extreme importance since otherwise the part may behave badly in practical application even if its design looks to be quite reasonable. The new proposed optimization procedure also proves to reduce the needed computational effort substantially.

Keywords

• lightweight design
• load-carrying structure
• topology optimization
• variable support conditions