Mechanical Behavior of Carbon/PEKK Thermoplastic Composite Tube Under Bending Load

Abstract

In an effort to develop thermoplastic composite tubes for helicopter landing gear applications, the mechanical behavior of straight tubes subjected to bending has been studied and presented here. It was found that interlaminar normal stresses of large values exist between layers located under the loading point. This can cause delamination between different layers at location under the loading point. The stiffness of the tube along the circumferential direction is important to prevent inward deformation under the load point, which can lead to buckling and sudden load drop. The absorption of energy upon fracture depends on the strategic placement of layers having different strain limits at proper locations along the thickness direction.