Dynamic Response and Energy Absorption Characteristics of Expansion Tubes Under Axial Impact

Abstract

The expansion tube is normally used in impact-resistant components, owing to the stable expansion force, and high specific energy-absorption capacity. This paper reports the deformation mechanism and energy absorption characteristics of expansion tube subject to impact velocity ranging from 0.083 m/s to 48.84 m/s. The effects of cone piston semi angle, tube wall thickness, and impact velocity on expansion tube performance were studied via experimental measurements and numerical modeling. The mechanical responses of the expansion tube were measured using a universal gas gun setup. The energy absorption capacity of the expansion tube absorber was identified to be different under quasi-static and dynamic compressions. The dynamic expansion force is lower than the quasi-static expansion force, which is about 62.2%-76.6% of the static expansion force, but the deformation mechanisms of the tube under quasi-static loading and dynamic impact are same. A finite element numerical model was built and validated with the experimental data. The finite element predictions were in good agreement with the experimental measurements. It was shown that the decrease in the friction coefficient is the main reason for the dynamic expansion force lower than the quasi-static expansion force. The influence of cone piston semi angle and tube wall thickness are significant on the energy absorption capacity of the tube. The dynamic expansion response does not change significantly when the impact velocity is less than 50 m/s. Under dynamic impact, the change of energy absorption efficiency is negligible, and the plastic deformation energy is about 64%-71.5% of the total kinetic energy of striker. INDEX TERMS Dynamic impact, energy absorption characteristics, expansion response, expansion tubes, friction coefficient.

A Novel Low-Velocity Impact Region Identification Method for Cantilever Beams Using a Support Vector Machine

“…Impacts occurring at velocities 1 to 10 m/s are treated as a low-velocity impact (LVI) by Cantwell and Morton [33], and LVI often creates damage with dent depths lower than barely visible impact damage, which attracted some scholars to investigate it. Jang et al [34] proposed a real-time impact identification algorithm for the composite flat plate under the low-velocity impact load, and Qi et al [35] investigated the effects of impact velocity on the performance of an expansion tube by the experiment method and numerical simulation. In view of the application of the support vector machine in pattern recognition problems [36][37][38], we put our focus on the low-velocity impact region identification method of cantilever beams.…”

Effect of Structural Parameters and Materials on the Mechanical Characteristics of Expansion Tube

“…The failure modes of tubular energy absorbers can be divided into the following types: buckling [8,9], tearing [2,10,11], expansion [12,13]. As shown in Figure 1, when a load is transmitted to the expansion tube, the cone piston is compressed into the tube [14]. As the diameter of cone piston is larger than the inner diameter of the tube, the tube gives rise to elastic and plastic deformation under the compression of cone piston.…”

“…In addition, the expansion tube enables to absorb energy through frictional dissipation between cone piston and inner wall of the tube. Due to the homogeneous deformation mechanism [14,15], constant expansion force [16], irreversible plastic deformation [17,18], light weight and high energy absorption capacity [19], expansion tubes have been frequently applied in many important fields in recent years [18,20], e.g. aircraft, aerospace, transportation and building, which are involved in cushioning.…”

“…Figure14. Plot of the configurations of the deformed tube from FE at successive semi angles of the cone piston, ranging from 3.82° to 45°: D =34 mm, S = 50 mm.…”