PSI - Issue 60

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Vaibhav Gangwar et al. / Procedia Structural Integrity 60 (2024) 123–135 Vaibhav Gangwar / StructuralIntegrityProcedia00(2024)000 – 000

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Table. 3. Comparison between three types of test systems Parameters Servo-hydraulic VHS

Split Hopkinson -150 0 C to 650 0 C (with additional chamber)

CEAST 9350 -70 0 C to 150 0 C (with dedicated environmental chamber) 0.8 m/s to 25 m/s (with additional accessories) Impact and blast

-100 0 C to Sub-ambient 250 0 C or induction of heating system upto 1000 0 C (if DIC is integrated with the system)

Operating temperature

Operational velocity

25 m/s

50 m/s

Automotive crash event 40 KN to 100 KN

Impact and blast

Purpose

100 KN

Maximum impact load Sensing Type of force sensor

15 KN

Piezoelectric load cell

Force is sensed by strain gauge mounted on bar 16 bar (air gasgun)

Strain gauge type 6 to 10 bar (compressed air)

280 bar (hydraulic oil)

Operating pressure

Strain rate achieved without additional accessories Strain rate achieved with additional accessories Cost of performing single experiment (Standard 2001b)

500 s -1

10 4 s -1

1500 s -1

10 3 s -1

>10 5 s -1

10 4 s -1

High

Low in comparison to VHS system Dedicated for only high strain rate tension, compression, and shear testing

Low in comparison to VHS system Tensile impact, Izod, Charpy, puncture and compression after impact (CAI)

High strain rate tensile test and dynamic fracture toughness testing

Type of testing

7. Conclusion 

In computer simulations of both the tensile test and the charpy impact test, the material parameters of the MJC_NP material model that were derived from tests performed in the INSTRON CEAST 9350 test system along with strain gauge provide a better prediction. It demonstrates that the material's properties from tests done with a drop-weight impact testing device are closer to the values needed for accurate numerical prediction.  The maximum velocity of drop-weight impact testing machine and servodydraulic test system is almost similar. Despite of this there is a limitation in high speed camera of DIC in terms of FPS.High FPS camera can be used but it will ultimate increase the cost of setup which have an impact on overall cost of testing per sample.  The servodyhraulic test system uses a piezoelectric load cell. This kind of load cell ringing intensity increases during high velocity tests. On the other hand, a CEAST 9350 strain gauge load cell from INSTRON is used. In comparison to piezoelectric load cells, this type rings less.  The test sample size required for tensile testing is very small compared to sample required in servohydaulic test system therefore the material requirement is less. It is estimated that from one tensile test sample of servohydaulic at least fifteen sample can be prepared to conduct test in CEAST 9350. Therefore, the cost of testing per sample is very low.  Investigations are still being going on the intermediate to high strain rate test results. Because of this, only tests for intermediate strain rates are done in this study, and the outcomes are quite good. As a result, it can fill the gap between the results of the high strain rate test and the quai-static strain rate test.