Development and validation of an automated FEM-based design optimization tool for continuum compliant structures

Abstract

This paper presents a design optimization method for continuum compliant structures. The developed optimization tool enables automated design, analysis and optimization of the compliant structures in a single simulation environment. The associated algorithm used automatically analyses the stress distribution occurring under certain loading and deformation conditions of initial designs defined by the user, adjusts a uniform stress distribution among individual flexure hinges by automated dimensioning and finalizes the design by integrating mechanical stops automatically matched with the kinematic capacity of individual hinges. In order to prove the advantages of the proposed optimization method, validation tests were performed under static and dynamic loading conditions. Results of the experiments showed that, compared to the non-optimized ones, optimized structures with the developed tool exhibit more uniform curvatures which indicate more even stress distribution among the individual hinges; up to 25% value increase in terms of maximum bearable load and maximum permissible deflection angle; less plastic deformation in case of overloading and up to 100% increased fatigue life.

Stress Dispersion Design in Continuum Compliant Structure toward Multi-DOF Endoluminal Forceps

“…The proposed method can derive parameters in almost real time, even using versatile numerical calculation software. Thus, the proposed method obtained the design parameters with a lower computational cost than the design method of previous research using FEA [24][25][26][27]. The results show the effectiveness of the proposed design method for successful motion generation.…”

“…In this regard, some studies have used FEA to improve the design of the joint structures [24][25][26][27]. For instance, Park et al [24] and Wu et al [25] evaluated the design optimization by changing the thickness of the hinge using FEA.…”

“…Furthermore, the thickness of the hinge varies along the structure. Coemert et al [27] presented the design optimizations by changing the thickness of the hinge for each segment using FEA to adjust a uniform stress distribution. The design optimization approach was validated using a 1-DOF compliant joint with three segments of elastic hinges.…”

“…The design optimization approach was validated using a 1-DOF compliant joint with three segments of elastic hinges. However, in these studies [24][25][26][27], a problem arose regarding the high computational cost due to the nonlinear analysis with fine mesh and the exploratory thickness determination of elastic hinges.…”

A handheld flexible manipulator system for frontal sinus surgery

“…It must be ensured that flexural elements have sufficient fatigue life to eliminate any possibility of malfunction during the procedure which could lead to critical consequences. Therefore, an FEM-based optimization tool was developed for flexure hinge-based continuum structures [24]. The developed algorithm automatically analyzes the stress distribution under certain loading and deformation conditions of initial designs defined by the user, adjusts a uniform stress distribution among individual flexure hinges by automated dimensioning and finalizes the design by integrating mechanical stops automatically matched with the kinematic capacity of individual hinges.…”