Study on behaviour of geometrically scaled glass reinforced epoxy tubes subjected to non-coincident quasi static-indentation

Purpose: The purpose of this paper is to study the behaviour of glass reinforced epoxy tubes subjected to repeated indentation loads at two non-coincident indentations 180° apart. Design/methodology/approach: Four geometrically scaled specimens ranging from 100 to 400 mm diameter were used in repeated indentation tests. Force, displacement and damage growth were recorded for loading and unloading until the indenter returned to its original starting point. Findings: Similar scaled trends were observed between the non-coincidental loadings. Unlike reported response form coincidental loadings, the responses from non-coincidental loadings yield lower values for bending stiffness and peak load. Research limitations/implications: The differences in behaviour of the specimen between non-coincident loadings were attributed to reductions in fracture toughness and circumferential modulus. Practical implications: Distant non-interacting damage and delamination around the circumference does reduce the structural performance. Originality/value: Behaviour of composite tubes under different loading conditions, for example low speed impact or quasi static indentation, is widely studied, however little attention has been given to the repeated loading incidents.