Search NASA⌕ Search

SEARCH · Search NASA

Results for “IMPACT TEST”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

On the measurement of hardness at high strain rates by nanoindentation impact testing

Recent advances in electronics have enabled nanomechanical measurements with very low noise, fast time constants and high data acquisition rates. Furthermore, these capabilities open the door for a wide range of ultra-fast nanomechanical testing. Given the inherent dynamic nature of high-speed testing, a thorough understanding of the testing system's dynamics and electronics is extremely important for accurate measurements. In this work, an analytical framework that includes the mechanical and electronic contributions of the instrument and the material constitutive response is presented to provide guidelines for performing high strain rate measurements of hardness by nanoindentation testing. Simple closed-form solutions that provide insights on the choice of test methodology, test parameters and instrument design are presented along with the strain rate range over which accurate measurements can be performed with the commercially available nanoindenters.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Dynamic Impact Testing of Rigid Polyurethane Foam

At the request of SRNL/Packaging Technology and Pressurized Systems, a Dynamic Impact Tester was developed by SRNL/Materials Evaluation that provides ease of use and the ability to test rigid polyurethane foam of various densities and sizes. In this initial testing comparisons were made between the properties of a currently approved foam product (General Plastics LAST-A-FOAM® FR3724) to those of an alternative supplier’s product (Paragon Dow Beta Foam). The basis for how the equipment and test methodology were developed is discussed. Overall, the testing showed very good correlation of energy absorption (ft-lb/in 3 ) versus %Crush data between General Plastics LAST-A-FOAM® FR3724 literature data and Paragon Dow Beta Foam on the Dynamic Impact Tester developed.

36 MATERIALS SCIENCE↗
DOE OSTI2024

High Speed Impact Testing of UHMWPE Composite Using Orthogonal Arrays

Abstract Background Ultra high molecular weight polyethylene composites are fiber based composites used in armor applications. While some characterization has been conducted experimentally, this study varies multiple parameters simultaneously to investigate material response under a wide range of conditions. Objective This work focuses on characterizing the response of Dyneema ® HB26 hard laminate composites under high-speed impacts to examine the influence of plate diameter, clamping pressure, and plate spacing on target performance. Additionally, micro Computer Tomography scans are used to nondestructively evaluate the damage evolution in the targets. Methods These scan results are used in concert with more traditional armor performance metrics to evaluate the effect of various parameters using the method of orthogonal array analysis. This technique allows for multiple variables to be investigated in the same test series, saving time and budget while still providing quality results across a range of variables and variable values. Results We conclude that of the parameters investigated, the plate spacing parameter has the largest effect on performance, followed by the plate diameter. Bolt torque was found to not have a significant impact on results, indicating that an edge clamping pressure is not critical to material response. Additionally, by examining the high resolution scans, we can quantify the damage with an effective damage angle and that this angle is a good predictor of performance. Conclusion Finally a damage theory involving the effective bending strength of the plates is discussed as an explanation for all of the results observed in this test series.

Hannah, T. (ORCID:0000000230261362)↗
DOE OSTI2013

Taylor Gun Impact Tests on Mock Comp-B Specimens

Twelve (12) Mock Comp-B specimens were received from Sandia National Laboratories in Albuquerque. Specimens were approximately 76.3 mm long and 15.8 mm in diameter. Weights varied from 21.23 to 22.14 grams, and various pieces had visible, mm-sized holes or gaps due to fabrication. Hand-marked lines, 1-centimeter down the length, were used in image analysis. Specimens were fired out of the Taylor gas gun and impacted on a brass anvil. High-speed images (25 μs per frame) were taken of the specimen during impact, with the camera 1) viewing through a boom box side port or 2) viewing from the top/front of the anvil through a Lexan window on the boom box. Side views are useful because they show silhouette contours of the specimen collapse. Top view images are useful because they show more clearly the time and strain at which fracture and fragmentation begins. We tested 4 specimen velocities: 133.5, 115.3, 87.8 and 74.5 m/s. At each velocity, at least one specimen was viewed from the side and one viewed from the top.

36 MATERIALS SCIENCE↗
DOE OSTI2020

GPHS Module Pre-Impact test Temperature Prediction with ANSYS [PowerPoint]

The purpose of the project was to: Develop a finite element thermal model of the General Purpose Heat Source (GPHS) Module loaded with four fueled clads; Perform steady state analysis to validate the thermal model via energy balance; Perform transient thermal analysis to predict clad temperatures at various times; and, Transient model results will be used to inform module soak time needed to reach a desired clad temperature prior to impact.

42 ENGINEERING↗
DOE OSTI2021

Impact Testing and Analysis of Modified Metal Slugs

This report summarizes initial results from a series of gun experiments which were conducted at the DICE facility. The target of these experiments was a modified metal slug composed of a tantalum/tungsten alloy (Ta-10W). The general geometry of the slug was a right circular cylinder with a through-hole cut normal to the cylinder's axis. In all experiments, hardened steel impactors were used, the desired impact velocity was 200 m/s, the slug was preheated to a target temperature of 175° C, photon doppler velocimetry (PDV) was used to measure the projectile velocity before and after impact, and the impact event was recorded with high-speed video. In two of the impacts the slug was oriented perpendicular to the projectile, while in the remaining two it was tilted 8° from normal. Initial high-speed speed video results showed slug failure in the tilted impact case, while the slug survived normal impacts. Recovery fixtures were used to preserve impacted slugs for future postmortem analysis. Discussions are included regarding improvements to potential future experiments involving these slugs.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2026

Multiple Hail Impact Testing

For resilient energy delivery PV modules and systems must withstand extreme weather events such as hailstorms, which are the leading cause of PV insurance claims. Currently, the industry testing is limited to one strike at a time, but in real hailstorms multiple hail strikes can occur within a fraction of a second. In this project we test if multiple simultaneous or near-simultaneous hail strikes cause more damage than with single hail strike testing.

14 SOLAR ENERGY↗