Study On Performance Of Circular Steel Pipes Under Lateral Impact

In addition to resist the dead loads, wind loads, seismic loads, snow loads, astructure may be subject to accidental loads during its life circle, such as blast andimpact loads. With the global situation of terrorism, the blast and impact loadsshould be considered in the design of certain important public structures. Since theimpact loads are transient and complicated, these problems are insufficient to besolved by theoretical analysis. What’s more, finite element simulations are lack ofcredibility. The impact test is the most accuracy way for the impact issues.Furthermore, it’s well known that the steel pipes are used commonly in steelstructures. Studying the response of steel pipes under impact loads could providetheoretical support for structure designing. In this paper, impact test technologywas fully investigated, which includes the experimental principles, test dataacquisition process. Besides, a48x3.5mm ERW pipe test was carried out. Finally,fully clamped steel pipes under various working conditions were studied by finiteelement package ANSYS/LS-DYNA. The main contents in this paper are shown asfollowings.1. Researching of impact test technologyThis paper summarized the impact tests in different fields, described theprinciple and data acquisition of impact test based on the strain rate. The drophammer system in HIT was introduced in detail, including the design of lighthammer, the data acquisition, the synchronous of high speed camera and otherattentions. The drop hammer system was verified with some impact tests.2. The lateral impact test of steel pipesThe impact tests were conducted with9ERW pipes with length480mm andthe other5specimen with lengths960mm, which are all the same cross-section48x3.5mm. During the whole tests, the strains were collected, and the processeswere recorded by a high-speed camera. Finally, the relationships between spansand failure modes, bending angles, dents were analysed.3. Finite element simulation of fully clamped steel pipesIn ANSYS/LS-DYNA, the impact models were created. With the varyingpipe’s sections, lengths, angles of impact and the heights of the hammer, a largenumber of simulations were conducted. The failure modes of pipe under differentconditions were obtained, and impact forces, exposure duration, energy qualitativerelationship between the above parameters were analysed as well.