Robust topology optimization of a flexural structure considering multi-stress performance for force sensing and structural safety

Abstract

This paper demonstrates a new robust topology design formulation for a compliant sensor structure considering multi-stress performance. Compliant mechanism design is one of the main applications of topology optimization that can be used to achieve displacement or force requirements based on its elastic deformation. Most compliant mechanisms have hinge joints where high stress is observed and this should be carefully considered in the design formulation. In this paper, we investigate a new design formulation that considers multiple stress components for force measurement and structural safety in a compliant mechanism-a wind tunnel balance. An internal wind tunnel balance is a multi-axis force sensor that measures aerodynamic forces and moments during wind tunnel testing. For the axial section of the balance, it is required to have substantial stress reading (sensor performance) by the axial load. In this paper, two stress measures are used in the design formation: (1) local directional stress to meet the sensor performance by a small axial force, and (2) normalized P-norm stress with a relaxation approach to ensure the safety of the balance by a large normal force. The high force ratio between axial and normal forces (1:10 +) is investigated in this paper. In addition, a robust approach is applied to reflect the manufacturing uncertainties from three different projected design variables. The manufacturable blueprint designs using this approach show satisfactory performance with respect to sensing and structural safety.

Influence of topology optimization parameters on the mechanical response of an additively manufactured test structure

“…It has solved design problems since first being introduced by Bendsoe and Kikuchi (Martin Philip Bendsøe, 1988). It has been applied to design functional structures/devices in medical (Al-Ali et al, 2017;Guo and Yin, 2019;Sutradhar et al, 2016;Wu et al, 2021), aerospace (Munk et al, 2019;Zhu et al, 2016), force transducer (Sung et al, 2022), energy harvesting (Rupp et al, 2009;Zheng et al, 2009), electromagnetics (Deng and Korvink, 2018;Im et al, 2003;Jung et al, 2021), and fluid flow system (Gersborg-Hansen et al, 2005;Guest and Prévost, 2006) applications. Manufacturability for the topology optimized structures is a consideration that needs to be addressed due the resulting complex shape (Liu and Ma, 2016).…”

Topology Optimization Design of an Active Deformable Mirror Based on Discrete Orthogonal Zernike Polynomials

“…It establishes the relationship between density and elastic modulus, takes the material density as the topological optimization design variable, and obtains the optimal distribution of structural materials through the presence or absence of materials. Compared with the homogenization method, the variable density method can directly obtain the relationship between the unit density and the elastic modulus without solving it again, which greatly reduces the variables of optimization design, simplifies the optimization solution process, and improves the calculation efficiency [8][9][10][11][12]. The evolutionary ESO method realizes structural topology optimization by imitating the biological evolution process and gradually deleting invalid or inefficient materials.…”