Fatigue characteristics of jagged pin-reinforced composite single-lap joints in hygrothermal environments

Abstract

This study aims to identify the reinforcing effects of jagged z-pins on the static and fatigue strengths of composite single-lap joints. We conducted tests on composite joints reinforced with jagged stainless-steel pins under the three environmental test conditions: room temperature and dry (RTD), elevated temperature and dry (ETD), and elevated temperature and wet (ETW). Test results showed that reinforcement with z-pins improved joint strength under all test conditions. In particular, when jagged z-pins were used under the ETW condition, static and fatigue strengths at a million cycles increased by 32.2% and 65.8%, respectively, compared with the corresponding values for an unpinned joint. When standard z-pins-without the jagged pattern were used, the static and fatigue strengths increased by 13.4% and 11.8%, respectively. In the future, if the jagged shape and pin density are optimized, we expect that the effect of z-pinning can be further improved. (C) 2014 Elsevier Ltd. All rights reserved.