{"id":35444,"date":"2021-01-06T18:12:07","date_gmt":"2021-01-06T18:12:07","guid":{"rendered":"https:\/\/www.simscale.com\/?page_id=35444"},"modified":"2024-06-24T11:58:24","modified_gmt":"2024-06-24T11:58:24","slug":"physical-contacts","status":"publish","type":"page","link":"https:\/\/www.simscale.com\/docs\/simulation-setup\/contacts\/physical-contacts\/","title":{"rendered":"Physical Contacts"},"content":{"rendered":"\n

Physical (or “nonlinear”) contacts enable you to calculate realistic contact interaction<\/strong> between two parts of the assembly. Also, it allows calculating the self-contact between different faces of the same part. Unlike linear contacts, those faces are not just connected via linear relations but the actual contact forces<\/strong> are computed.<\/p>\n\n\n\n

To enable a nonlinear interaction, you have to define contact pairs of faces or face sets. For those faces the distance between each other is tested during the simulation, and, in the case that a face pair gets in contact, the interaction forces are taken into account, preventing those faces from interpenetrating each other. As those forces only occur in the case of contact the interaction is a nonlinear phenomenon and thus only applies for nonlinear analyses<\/strong>.<\/p>\n\n\n\n

The Physical contacts<\/em> settings panel offers the following choices:<\/p>\n\n\n

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\"physical<\/a>
Figure 1: General Physical contact settings panel, for Fixed point<\/em> method (left) and Newton<\/em> method (right)<\/figcaption><\/figure>\n<\/div>\n\n\n

The physical contact solution algorithm works by performing two independent steps:<\/p>\n\n\n\n

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  1. Compute the non-linear deformation of the geometry (Nonlinearity Resolution)<\/strong>: The deformation of the geometry due to the boundary conditions is computed at the beginning of each time step, without taking into account the physical contact condition.<\/li>\n\n\n\n
  2. Compute the contact compliance condition (Contact Nonlinearity Resolution)<\/strong>: The interpenetration between contact pairs is computed, and the geometry is updated accordingly to enforce the physical contact condition. Then, the contact pressure is computed and the forces are registered for the next time step.<\/li>\n<\/ol>\n\n\n\n
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    <\/i>Contact Pressure Field<\/p>\n <\/div>\n

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    The contact pressure field can be queried to the solver under Result Control Item > Solution fields > Contact type > Pressure. <\/i>\r\n\r\nThis field will only be non-zero on the slave assignment of the contact pairs.<\/p>\n <\/div>\n<\/div>\n\n\n\n

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    <\/i>Heat Transfer<\/p>\n <\/div>\n

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    In Thermomechanical Analysis<\/a> , the physical contacts <\/em> do not transfer heat. If you would like to add heat transfer, you need to create an additional bonded contact <\/em> with heat transfer only <\/em> option. Of course, this scenario considers the faces to be in perfect thermal contact, even if they are not mechanically in contact.<\/p>\n <\/div>\n<\/div>\n\n\n\n

    The following general parameters are available for the global physical contact algorithm:<\/p>\n\n\n\n