Transient Response of a Pultruded Fiber-Reinforced Plastic Rod Subject to Impact Loading

Abstract

This work is concentrated on investigating the transient response of a pul truded fiber-reinforced plastic rod subject to impact loading. Both impact tests and corre sponding numerical simulation are performed. The target rod made of S-glass/epoxy, with a diameter of 9.7 mm, is clamped on one end. The other end of this rod is struck by a cy lindrical flat-ended steel rod weighing 16 gm. The diameter of the impactor is equivalent to the target rod. A pneumatic gun is utilized to launch the impactor with a velocity up to 60 m/s. The dynamic response of the composite rod is detected by using a pair of strain gages (TML, type FLK-6-11, 120 Ω) and associated facilities. A digital oscilloscope (Nico let 4094C) is used here to record transient signals. Several tests have been conducted in order to obtain the longitudinal waveform of the composite rod due to impact loading. Corresponding numerical simulation based on explicit Lagrangian finite element method is also performed to check against experimental observation. This code is capable of han dling the orthotropic constitutive relationship, large displacement mechanism, and also the lateral effect. Numerical results show that the pulse duration agrees well with test findings. However, the computed peak longitudinal strain is greater than that of the test result. This discrepancy is due to employing the static mechanical properties in numerical analysis. It is found that the computed peak longitudinal response agrees more closely with the test result when corresponding mechanical properties, such as Young's modulus, are increased. This increment is expected for composite material under high strain rate loading.