Compressive split Hopkinson pressure bar testing

• Main Author: Jayapragash S/O Muthazhagan
• Other Authors: Shu Dong Wei
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Materials::Material testing and characterization
• Online Access: https://hdl.handle.net/10356/157957
• Institution: Nanyang Technological University

Static mechanical parameters like hardness and strength can now be easily obtained from a variety of online sources. However, most of the available data neglects the fact that a material's mechanical properties are, in general, strain rate dependent. Even though it was observed that materials reacted differently in quasi-static and high strain rate circumstances, this knowledge is not widely available. High strain rate qualities are particularly relevant in applications where materials are subjected to dynamic stress, such as the automotive and aerospace sectors. The Split Hopkinson Pressure Bar (SHPB) technique has been used to determine material properties at high strain rates for many years. It can be used to test materials deformation at high strain rates of 10^2 to 10^4 s^(-1). The deformation history of the specimen is retrieved from the signals in the strain gages positioned on the incident and transmission bars in traditional SHPB analysis. This report will detail the findings of the compression tests conducted with the SHPB. However, the SHPB is capable of conducting tests under tension and torsion as well. The setup used for this study was calibrated to ensure that the pressure bars were aligned, and strain gauges were mounted on the incident and transmission bars. Tests without specimens also known as dry runs were carried out to gather experimental values before testing with specimens. This enabled essential measurements to be taken to verify that the specimen tolerances were satisfied. These were crucial towards ensuring the experiment's success and reliability. Aluminium alloy Al 6061-T6 specimens were used in a variety of tests, including empty runs, calibration runs, striker bar velocity tests and tests with various pules shapers. The gathered data was compared with data from previous studies and literature to assure correctness and authenticity.