Authors: K Sylves K Maute M L Dunn
Publish Date: 2008/07/29
Volume: 38, Issue: 5, Pages: 455-
Abstract
Tailoring adhesive properties between surfaces is of great importance for microscale systems ranging from managing stiction in MEMS devices to designing wallscaling geckolike robots A methodology is introduced for designing adhesive interfaces between structures using topology optimization Structures subjected to external loads that lead to delamination are studied for situations where displacements and deformations are small Only the effects of adhesive forces acting normal to the surfaces are considered An interface finite element is presented that couples a penalty contact formulation and a Lennard–Jones model of van der Waals adhesive forces Two and three dimensional design optimization problems are presented in which adhesive force distributions are designed such that loaddisplacement curves of delaminating structures match target responses The design variables describe the adhesive energy per area of the interface between the surfaces as well as the geometry of the delaminating structure A builtin length scale in the formulation of the adhesion forces eliminates the need for filtering to achieve comparable optimal adhesive designs over a range of mesh densities The resulting design problem is solved by gradient based optimization algorithms evaluating the design sensitivities by the adjoint method Results show that the delamination response can be effectively manipulated by the method presented Varying simultaneously both adhesive and geometric parameters yields a wider range of reachable target loaddisplacement curves than in the case varying adhesive energy alone
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