Experimental Study on the Effect of Two Equal-Sized Holes Lying at Different Angles in a CFRP Plate under Bending

摘要

A bending test method was designed to investigate the failure characteristics of drilling carbon-fiber reinforced composite(CFRP)plates.The CFRP plates were fabricated and drilled to join other parts for use in aircraft structures(riveting or bolting).Each sample had two equal-sized holes at 0,θ,or-θ degrees at a fixed distance of 36 mm in the longitudinal direction.The sample dimensions were identified following a study on tensile testing single-holed samples based on the ASTM D5961 standard.The tensile test focused on three cases of laminate:[0]_(14),[22.5]_(14),and[45]_(14).The maximum mean forces for[0]_(14),[22.5]_(14),and[45]_(14)laminate configurations were 6.32,6.59,and 7.12 kN respectively.These results were implemented into a bending test which included two configurations of laminate:[0]_(14)and[45]_(14)and two equal-sized holes with a variable distance of 0 and 9 mm in the transverse direction of the plate.The bending test configuration is presented in this paper.The results revealed different load-bearing capabilities in each of the three types of specimen configuration.Samples with two holes lying at ±θ degree affected the overall strength in the[45]_(14)case,and as in[0]_(14)there was no difference between the eccentricity and the aligned holes.In[45]_(14),the eccentricity decreased the maximum allowable force by 1.57 percent in the normal eccentricity case and by 15.94 percent in the alternate eccentricity case compared to the aligned case.