Hi,
Is there a direct way to reproduce numerically in Abaqus the strain recorded by a full Wheatstone bridge measuring the Poisson’s effect as in SHPB bars.
Thanks
Do you mean, modelling the complete Hopkinson bar and reproducing the strain signals you got in the experiments?
Yes Faye, I used skins both on the incident and transmitted bars for collecting strains in the full SHPB model. For a SHPB instrumented with half bridges with thermal and bending compensation, I got a good correlation numerical-experimental . For the SHPB equiped with full bridges measuring the poisson's effect, I got approximately the same amplitude for strains but not the same shapes . I thought since LE22 gives the longitudinal strain.
I want to reproduce the strains with the same tendency.
It is difficult to answer why you are not getting a good match with full bridge signal. However, looking at the attached figure, it seems that length of the incident waves are not matching, so I was curious on what is going as input in your simulation?
Not only this fact is curious.
Time between negative incident wave and first positive wave is also different. It probably means that you "measured" the strain in model in different point (closer to the end of incident bar?) than in experiment.
Dear All,
@Faye: The incident waves have the same duration but the problem was in the difference between their shapes . In the full model, I used a striker of 20 mm in diameter and 0.8m in length with a rounded Tip. The input was a striker's velocity of 6.2 m/s which was introduced in the predefined field .
@ lluk: Ok , the beginnig of the numerical reflected pulse was shifted to match the experimental one by introducing the good incident gage location to the interface IB/Specimen as shown in the new attached figure but it remains the negative part of the reflected strain that tends to zero.
Thanks a lot,
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