本文件描述了一种测量软弹丸或易碎弹丸与相对坚硬的平坦法向表面之间碰撞时的力的方法。该文件描述了所需的硬件和仪器，以及计算力所需的处理和数据简化。在这项测试中，一枚弹丸撞击一根两端扁平的长圆柱杆的一端，称为霍普金森杆。冲击发生在杆的轴向中心线上。与弹丸的横向尺寸相比，圆柱形杆的直径较大，因此，在撞击期间和之后，弹丸材料会径向或向后移动，而不是在撞击表面周围挤压。在距离受冲击端一定距离处，用应变计测量钢筋的纵向应变。杆必须足够长，以便冲击持续时间小于冲击产生的瞬态应力波到达杆端并返回应变计位置所需的时间。 本试验旨在测量弹丸撞击圆柱杆时产生的瞬态力。在该测试期间，还可以捕获弹丸破碎模式数据。与杆材料相比，弹丸材料预计较软。与钢筋材料的屈服强度相比，冲击应力预计较小，因此钢筋中的所有变形都是弹性的。以国际单位制或英寸-磅单位表示的数值被视为单独的标准。每个系统中规定的值可能并不完全相等；因此，每个系统都必须被视为独立的。本标准并未解决与其使用相关的所有安全问题。本标准的每个用户都有责任确保任何安全问题得到适当解决。

This document describes a method for measuring forces during an impact between a soft or frangible projectile and a relatively rigid flat normal surface. The document describes the hardware and instrumentation required, as well as the processing and data reduction required to compute force.In this test, a projectile impacts one end of a long cylindrical bar with flat ends, called a Hopkinson bar. The impact occurs on the centerline of the bar in the axial direction. The diameter of the cylindrical bar is large compared to the lateral dimension of the projectile so that, during and after the impact, the projectile material moves radially or backward, rather than extruding around the perimeter of the impact surface.The bar is instrumented with strain gages at some distance from the impacted end to measure the longitudinal strain in the bar. The bar must be sufficiently long so that the duration of the impact is less than the time it takes for the transient stress wave generated by the impact to travel to the end of the bar and back to the location of the strain gages.This test is intended for measuring the transient force generated by the projectile when it impacts the cylindrical bar. Projectile breakup pattern data may also be captured during this test. The projectile material is expected to be soft compared with the bar material. Impact stresses are expected to be small compared with the yield strength of the bar material so that all deformations in the bar are elastic.The values stated in either SI units or inch-pound units are considered separate standards. The values stated in each system may not be exactly equivalent; therefore, each system must be considered as independent.This standard does not address all of the safety concerns associated with its use. It is the responsibility of each user of this standard to ensure that any safety issues are properly addressed.