Difference in cohesive zone model results peak force for the same input data

[abc123ali]

Respected ABAQUS Users, I have made two same cae abaqus cohesive zone model but just with a difference of surface to surface contact in one model and node to surface contact in another model gr8 and gr9 respectively in the interaction module and I got different results. Kindly solve this problem.These both model have 8 number of grooves. In the cohesive zone modelling of the grooved structure when there is increase in number of grooves it should come more cohesive force during the shear slipping of both plates but it reduces in one model but in another model it comes more using node to surface contact. Kindly update which one is correct or how to model correctly? The number of grooves in JobGRNTOSUR contains 4 grooves with node to surface interaction while the surface to surface is gr1fm has surface to surface interaction when this is compared with 8 groove model should have low cohesive peak force due to less area of contact but it is more than gr8 surface to surface contact. Also please tell me that the reference point I just made is rf1 while it appears as assembly constraint 3 reference point in xy obd field output element nodes section during extraction output. why?
Thanks for cooperation

 

[FEA way]

In practice, the main difference between surface to surface and node to surface contact is in the accuracy/uniformity of results such as contact pressure. So compare CPRESS and CSHEAR contour plots. You can also check other results such as COPEN and CSTATUS to see how contact works in those models.

 

[abc123ali]

Respected ABAQUS Users, which filed output option is activated to get these output in the history output manager in the step module. As I just found CSTRESS and PPRESS but not CPRESS. I didnt find CSHEAR, COPEN, CSTATUS. Kindly guide me.
Thanks for cooperation

 

[abc123ali]

Respected ABAQUS Users, the analytical solution for this shows a big error in the output stress of 24% as when the grooves are made the enhanced area should give the peak value of force to 347 N as when the input nominal value of stress is 3.1 MPa which yields 347N peak while here the model give output of only 250 N for the 4 peak with the height of peak as 1.
Thanks for cooperation

 

[abc123ali]

Respected ABAQUS USERS, As I have used C3D8R and all the structure is made using tie command by making a big thick plate with the strips and then attached by using tie in the interaction module otherwise if the structure is continuous by making grooves using the extrusion of the thick rectangular plate then the mesh near the groove edges of the grooves and some regions is not cubical and gives totally erroneous results. Kindly update it. Thanks for cooperation

 

[FEA way]

which filed output option is activated to get these output in the history output manager in the step module. As I just found CSTRESS and PPRESS but not CPRESS. I didnt find CSHEAR, COPEN, CSTATUS

Request CSTRESS to get CPRESS and CSHEAR. Request CDISP to get COPEN and CSLIP. CSTATUS is shown directly under Contact in the Field Output Request dialog.

If you want to consult some doubts regarding the correctness of the mesh, you will have to share some screenshots or the model itself.