Low velocity impact response of GFRP laminates subjected to cycling moistures

The low velocity impact response of laminated composites in ambient hygrothermal environments has been extensively investigated. This response, however, is not well understood when subjected to moisture cycling at elevated temperatures. In this current study, two types of glass fiber reinforced plastic (GFRP) laminates, unidirectional and crossply, were conditioned in a conditioning chamber for a maximum of eight moisture cycles at conditioning temperatures from 50°C to 100°C. Low velocity impact tests were conducted on the conditioned specimens and control specimens via an instrumented drop‐weight impact testing machine. The tension after impact (TAI) strength was investigated using an MTS machine. The equivalent damage size is obtained using an average stress criterion found in the literature. The effect of moisture cycling and conditioning temperatures on the low velocity impact response and residual load carrying capacity of GFRP laminates are evaluated via the test results.