An Instrumented Drop Tower for Impact and Stab Testing

Published

September 4, 2026

Author(s)

Alexander Landauer, Ran Tao, Amanda Forster, Aaron Forster, Michael Riley

Abstract

This report describes a 4 m instrumented drop tower (IDT) system in use at the National Institute Of Standards and Technology (NIST). Drop tower systems are a relatively common means of testing various impact-like scenarios, often for armor or padding materials, with controlled impacts at known energies. Although originally designed for standardized stab testing, the capabilities of this IDT have been expanded. In this implementation the system is instrumented to measure accelerations, forces and force distribution, impact velocity, and test piece deformation. It is modular, with configurable impactor mass, geometry, drop height, specimen or test artifact type, and fixturing. Thus, the drop tower system is suitable for stab testing, impact testing, material characterization, and other related measurements on artifacts ranging from from whole armor and helmeted headforms to specimens of novel impact mitigating materials. Two illustrative examples are provided in this report: characterization of helmet liner foam and stab testing of a novel armor prototype.

Citation

Technical Note (NIST TN) - 2381

Report Number

2381

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.TN.2381

Local Download

Keywords

Armor, Foam, Helmets, Impact, Material testing, Protective equipment, Stab, impact mitigating materials

Citation

Landauer, A. , Tao, R. , Forster, A. , Forster, A. and Riley, M. (2026), An Instrumented Drop Tower for Impact and Stab Testing, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2381, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=962553 (Accessed September 5, 2026)

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