Development of a New Method to Investigate Dynamic Friction Behavior of Metallic Materials Using a Kolsky Tension Bar
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Understanding the interfacial behavior of two materials sliding relative to each other is import ant in computational modeling and simulating impact or shock response of components, subsystems, and even full-scale systems. Although often considered as a constant for different applications, the coefficient of friction may be dependent on a number of factors such as normal force, roughness, material type, temperature, and sliding velocity. In this study, a new method based on a Kolsky tension bar with a custom-made friction fixture was developed for measurement of the dynamic friction coefficient between two metallic materials at high sliding velocities. In this new method, polyvinylidene fluoride (PVDF) thin film force sensors were used to measure the normal force, while a strain gage on the transmission bar was used to measure the friction force. As such, the dynamic friction coefficient is calculated with the normal and friction forces. The impact velocity can be varied to investigate the dependency of friction coefficient on impact velocity. To evaluate the technique, friction coefficients between 4340 steel and 7075-T6 we re measured at three different sliding velocities of 4, 8 and 11 m/s. Effects of surface roughness, normal force, and impact speed were also explored . Decreased static and kinetic friction coefficient s were observed when the normal force was increased at constant sliding velocity. With increasing velocity, the friction coefficient remained fairly constant for the three velocities studied. Higher friction coefficients were measured when the specimen roughness was increased.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- AC04-94AL85000; NA0003525
- OSTI ID:
- 1596207
- Report Number(s):
- SAND-2017-11985; 658217
- Country of Publication:
- United States
- Language:
- English
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