
The two cases differ in the orientation of the cohesive elements with respect to the applied load. In the first case, all three cohesive elements are perpendicular to the applied force, so that only normal tractions and separations will be present on these cohesive elements, with the second having an inclined cohesive element that will have both normal and shear tractions and separations.
In the upcoming sections we will present the three main insertion methods, which include blind insertion, insertion with damping, and prestretched insertion. From our 1D analysis, we have determined that the solution for a dynamic insertion problem is dependent on the stress level of the cohesive element at the time of its insertion. Using the average stresses for volumetric elements and , the cohesive elements are inserted at time steps 0 ( ), ( ) or ( ) of a ( ) time step simulation. corresponding to stress levels of , and , respectively, as seen in Figure 4.7. In each case we will follow the nodal separation of the tracking node presented in Figure 4.6.
