High Strain Rata Material Testing Materials undergo high strain rates deformation in various applications, e.g. accidental events such as explosions and penetrations, and engineering applications such as crash worthiness of vehicles, bullet proof armors, impact resistant pressure vessel and shipping cask for transport of nuclear materials. In addition to this, forming processes like extrusion, rolling and high speed machining can also result in high strain rate deformation. For the optimal design and safety analysis of components seeing high strain rates of loading the constitutive behavior of materials at high strain Dynamic testing of material is becoming more important due to the need for more optimized crashworthiness and impact analysis. Positive strain rate sensitivity, i.e. the strength increases with strain rate, offers a potential for improved energy absorption during a crash event. The load can be an instant load wave used for very high strain rate. The machine will also have the proper measurement systems to measure and record the important parameters, such as strain, displacement and load. Split Hopkinson Bar system, Single Bar (SB) system is the systems commonly used. The systems has been developed by Adavnce Instrument Inc. in recent years to meet the increasing demand for dynamic testing. Loading Device Specimen Transmitter bar Momentum Bar Stain Gages Principle of Split-Hopkinson Pressure Bar Split-Hopkinson bar (SHB) works on the principle of one dimensional wave propagation, its main components are a gas gun, a striker bar, an incident bar and a transmission bar. The striker bar sits in the barrel at the gas gun chamber. The incident bar, transmission bar and striker bar are all made of same material and same cross-section area. At all times during the test the striker, incident and transmission bar should remain elastic. The sample to be tested is sandwiched between the incident and transmission bar. The striker bar is propelled by gas pressure towards the incident bar. On impact, an elastic compression wave propagates down the incident bar toward the sample. On reaching the sample, repeated wave propagation within it deforms it plastically. Part of the wave goes through to the transmission bar (transmitted pulse) and part is reflected back into the incident bar (reflected pulse), each of which is picked up by the strain gauges mounted on the corresponding bars. Strain gauges on each bar are mounted to the axial strain. Elastic strain generated in incident and transmission bar are used to calculate the stress-strain in the sample.

SHPB SHTB Test Apparatus Advance Instrument Inc's designs a number of conceptual for SHPB were thought of and the optimized design was worked out The precision tolerance, straightness in bars and design and proper functioning of pneumatic gun were met This setup has been used extensively to study the high strain rate material behavior. The system consists of the dynamic loading units, data acquisition and control system and spare parts & tools. The facility is designed for Split Hopkinson Bar Compression high strain rate testing. The system can be equip with high temperature heating system and...

Although there are various setups and techniques currently in use for the Split-Hopkinson pressure bar, the underlying principles for the test and measurement are the A split Hopkinson pressure bar (SHPB) is a test apparatus used to obtain the material properties at 10^2 to 10"5 s-1 high strain rates. The specimen[1] is placed between the ends of two straight bars, called the incident bar[2] and the transmitted At the end of the incident bar, a stress wave initial pulse[4] is created which propagates through the bar toward the This wave is eferred pulse[5] to as the incident wave, and upon reaching...

SHPB SHTB Test Apparatus pulse signal recorded True stress vs. true strain curve A constant nominal strain rate throughout ttie test is essential to the quality of data. The strain rate must be calculated during the test to insure that a constant rate is achieved Local snapshot Ah™ uross-aactlonal Area ot Bars A. ■ Cro&s-sectiorial Area of Specimen Fi# = Yming'ft ModuluA nf n^r?v Ch ■ Wave Propagation Velocity Strike Velocity measurement system& Trigger system Two Laser beam and phototransistor pairs are used to measure the velocity of the striker bar. A set pre-trigger value also acquires data...

The split-Hopkinson pressure bar setup facility developed at Advance Instrument Inc. Those set-up can be used to test material in strain rate range of 102 s-1 to 10 s-1 . Those system have contributed immensely in material property characterization under dynamic loading condition and its application in safety related research. The system can be delivered including the pieces of equipment; installation,training and technical consultation as complete turnkey bases. Apparatus Type : Compression, Tension or Torsion 'Dynamic loading units • Pressurized Striker Bar Launcher ■ Bar System: Dim & Length...

Advance Instrument Inc._\vww.advanccinstrumcnt.com Split Hopkinson Pressure Bar Tester Basic Requirements Providing as much information will lead to a more accurate costing and time saving. Please include measurement units wherein applicable. Use a separate new form should there be any second requirements of different parameters. Name: Phone: Country or Province: Email: PRICING REQUESTED IS: □ ESTIMATED (FOR BUDGET PREPARATION) □ FIRM {FOR IMMEDIATE ORDER PLACEMENT USAGE) TEST SPECIMEN SPECIFICATIONS Material Code: ; : Material Description: Material physical properties in the still tensile /...