Some Aspects on the Elastic Behavior of a Bimetal Considering the Sensitivity of the Thickness of the Layers

Bimetals are usual designed by use of analytical formulas based on the beams theory from the Strength of materials. The paper presents a FEA study of a bimetal beam with two layers: Invar and Copper. The sensitivity of the thickness of layers was considered for: equal layers thickness, thickness calculated with a formula recommended in classical literature for optimizing the deformation (based on the Young modulus of the components) and several intermediary thickness values. For the case of the equal layers thickness the results from FEA and analytical formulas are compared. For all the studied models stress and deformation components from the longitudinal symmetry plane area are presented by comparison. The CAD and FEA models were developed within the FreeCAD open-source package.