August 14, 2019 at 7:58 amRoyalFlowersSubscriber
Hello every one,
I have a question about contact detection methods.
Does the Gauss point which is a default contact detection method work for all situations?
Recently I have faced a model with surface-corner contact (as following pictures) and realized that Nodal detection method (Normal to Target) provide different results than Nodal-Normal to Contact and Gauss Point methods.
It is clear that results should be different between contact normal and target normal because smoother surface should be selected to define normal directions. And in this case our contact area is a facet surface which results in multiply normal directions and software considers the average of them. But I cannot understand why results of Gauss Point method are different. And could we use Gauss Point as contact detection method for this case?
I would be thankful if someone could advise me in this regards.
Best regards, Shabnam Samsami
August 15, 2019 at 2:32 amSandeep MedikondaAnsys Employee
See, section 3.9.6 in the help. Depending on other settings such as normal stiffness, frequency of update, trim contact etc the restoring forces can be different which can explain the differences.
August 15, 2019 at 1:23 pmRoyalFlowersSubscriber
Thanks a million for you answer regarding this point. The all settings of model were the same and I only changed the contact detection method from Nodal-Target to Gauss Point. And the displacement of loading point was changed from 1,38 mm for Nodal-Target to 1,18 mm for Gauss Point. And the corresponding experimental value is 1,5 mm. Now I do not know why two different contact detection method resulted different outputs and which one should be taken. Also, could you please explain me what is restoring force?
Moreover, As I read "for a model with an edge or corner in contact we may need to consider contact detection at the node locations. In Figure 1 the red circles represent pin ball radius around the detection point. With integration point detection option, the element corner penetrates into the target element before contact is detected". Hence how can I check the penetration before contact detection (as figure 1) to confirm that Gauss detection method can not identify the edge of contact surface?