Influence of damage style on tensile and compressive properties of three-dimensional braided composites

The longitudinal tensile and compression tests were conducted on the pre-damaged three-dimensional braided composites.The varying rules of tensile and compressive properties and the failure mechanism of the mater-ials were investigated. Four kinds of damage processes were discussed,single-edge cut on the width,single-edge cut on the thickness,double-edge cut on the width and edge cut on the thickness and width.Experimental results reveal that the cut edge on the width of specimen barely affects the longitudinal properties,except that the compressive modulus deduces by 20%;while cut on the thickness makes a relatively great deduction on the properties.When the surface angle is 20°,stress-strain curves of tension and compression tend to linearity,and the failure mechanism has brittle fracture characteristics;when the surface angle is 35°,the stress-strain curves of compression express non-linearity to some extent.