• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1131-1137
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• 2017

Recently, regulations on fuel efficiency and $CO_2$ emissions have been reinforced in automobile industries. As a result, many companies make an effort to satisfy these regulations by adapting composite materials to the automobile body as well as its components. In particular, the lower control arm in the suspension system is subjected to heavy loads and is designed to be thick to meet operating loads. Therefore, it is essential for the lower control arm to reduce weight and to secure the durability assessment. In this paper, we conducted structural analysis by performing stress and stiffness analysis under given load conditions through finite element analysis, and verified whether it satisfies the load and stiffness conditions. The inertia relief method is adapted to the process of analysis, and the principal stress is used as a criterion for evaluation. Based on these results, the durability assessment is carried out using the stress-life method.

• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.389-396
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• 2016

The necessity for environment-friendly material development has emerged in the recent automotive field due to stricter regulations on fuel economy and environmental concerns. Accordingly, the automotive industry is paying attention to carbon fiber reinforced plastic (CFRP) material with high strength and stiffness properties while the lightweight. In this study, we determine a shape of lower control arm (LCA) for maximizing the strength and stiffness by optimizing the thickness of each layer when the stacking angle is fixed due to the CFRP manufacturing problems. Composite materials are laminated in the order of $0^{\circ}$, $90^{\circ}$, $45^{\circ}$, and $-45^{\circ}$ with a symmetrical structure. For the approximate optimal design, we apply a sequential two-point diagonal quadratic approximate optimization (STDQAO) and use a process integrated design optimization (PIDO) code for this purpose. Based on the physical properties calculated within a predetermined range of laminate thickness, we perform the FEM analysis and verify whether it satisfies the load and stiffness conditions or not. These processes are repeated for successive improved objective function. Optimized CFRP LCA has the equivalent stiffness and strength with light weight structure when compared to conventional aluminum design.