Characterization of material property at intermediate strain rate is important in vehicle crashworthiness design. However, severe oscillations known as system ringing often exist at this range of strain rate, leading to undesirable data quality. Based on the two intermediate strain rate test machines in authors’ lab, including a hydraulic machine and a drop tower system, an experimental/numerical study is carried out to analyze the ringing phenomenon. Two principles for design of the load measurement chain derived from the simplified mass-spring-damper model and the structure of customized load sensor are concluded, and the practical designs and setups for reducing ringing are introduced. Finite Element models of the two test machines are constructed and different parameters in the design of the test setup and the tested specimens are studied based on the numerical simulations. Results show that the level of the system ringing largely depends on three aspects, the condition of the impact surfaces, the material properties and the test strain rate. Differences and similarities of the two test machines are discussed and the methods to reduce the oscillation are summarized.
