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Figure 16. Instron TM mechanical grips (left) and Instron TM servohydraulic grips (right).
Figure 17 illustrates the simulated parts in the finite element model. Because of
symmetry, only half of the clamps is modelled, which reduces calculation time. The
corresponding symmetry boundary conditions have been imposed on the specimen. To further
reduce computation time, a rigid body constraint is placed on part of the housing cylinder of
the wedge grips, only the area where the cylinder makes contact with the grip is left
deformable. Furthermore, a part that models the wedge is added, also with a rigid body
constraint to reduce calculation time. The reference point of this part is given a certain
downward displacement. This part represents the hydraulic plunger in the hydraulic clamps.
Figure 17. The simulated clamps in the finite element model [45].