Low velocity impact response of GFRP laminates subjected to cycling moistures

The low velocity impact response of laminated composites in ambient hygroth ermal environments has been extensively investigated. This response, howeve r, is not well understood when subjected to moisture cycling at elevated te mperatures, In this current study, two types of glass fiber reinforced plas tic (GFRP) laminates, unidirectional and crossply, were conditioned in a co nditioning chamber for a maximum of eight moisture cycles at conditioning t emperatures from 50 degreesC to 100 degreesC. Low velocity impact tests wer e conducted on the conditioned specimens and control specimens via an instr umented drop-weight impact testing machine. The tension after impact (TAI) strength was investigated using an NITS 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 veloci ty impact response and residual load carrying capacity of GFRP laminates ar e evaluated via the test results.