This paper investigates the effect of temperature on hybrid and non-hybrid woven composite panels (100mm×100mm×6.35mm) drop-weight impacted at five different temperatures:−60°C,−20°C, room temperature (R.T), 75°C and 125°C. The studies were conducted by combining experimental and 3-D dynamic finite element (FE) approaches. The specimens tested were made of plain-weave hybrid S2 glass-IM7graphite fibers/toughened epoxy. The composite panels were damaged using an instrumented drop-weight impact tester equipped with an environmental chamber for temperature control. The time-histories of impact-induced dynamic strains and impact forces were recorded. The damaged specimens were inspected visually and using the ultrasonic C-scan method. A 3-D dynamic finite element software package, with Chang-Chang composite damage model, was then used to simulate the experimental results of the drop-weight tests. Good agreement between experimental and FE results has been achieved. It is observed that the variation of results obtained from our experiments for the hybrid composites was very small (about 8%) when compared to those of non-hybrid composites. Also, when looking at the hybrid or non-hybrid composite, the effect of temperature at −60°C, −20°C was not significant whereas at 75°C and 125°C the results were more distinct.
Drop weight impact measurements of HE sensitivity: modified detection methods