Strength of Mild Steel at High Strain Rate

The compressive yield point and the flow stress to cause a certain amount of compressive strain of 0.03%C steel were obtained experimentally within the range of strain rates of 2∼200/sec. The ratio of dynamic yield point to static yield point is 1.6∼2.5 and the ratio of dynamic flow stress to static flow stress is 1.0∼1.6. The yield point and flow stresses begin to be affected evidently by the strain rate in the region of the strain rate of more than 1/sec. And the stresses increase rapidly in the region beyond the strain rate of 100∼200/sec. By the repetition of impacts, the strain increment caused by one blow decreases with the repeating of impact. But at low stresses, the early blows cause very small strain and the strain is produced appreciably thereafter.