# How to treat a body as rigid? **URL:** \ **Category:** General Questions\ **Created:** [November 22, 2023, 6:55pm UTC](https://prepomax.discourse.group/t/how-to-treat-a-body-as-rigid/1279 "2023-11-22T18:55:44Z")\ **Posts on this page:** 1\ **Showing post:** 15
**Author:** ![synt](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/synt/32/4658_2.png) [@synt](https://prepomax.discourse.group/u/synt)\ **Post date:** [December 7, 2023, 9:24am UTC](https://prepomax.discourse.group/t/how-to-treat-a-body-as-rigid/1279/15 "2023-12-07T09:24:33Z")
hi, i look the problem sketch and seems to be possible in CCX for all element type (beam, shell and solid). Since there are two member connected share the same common nodes, it is a convenient way using Remove in Equation. Some rotational DOF for beam and shell element model, translation in longitudinal axes for solid element model. to make a member rigid, it can be simple assign to element set, reference nodes is optional and not mandatory. is the “m” denotes to mass? if yes, there will be rotational inertia to be considered. Different element type (beam, shell, solid) required specific approach in this regard or simplify by using distributed mass instead of lumped. lastly, about load scheme in static or dynamic. When static being conducted, make sure all load in equilibrium since the model prone of stability. p.s for reference example used > [@Possibility to generate MPC](https://prepomax.discourse.group/t/possibility-to-generate-mpc/65): > > this is from [FreeCAD forums](https://forum.freecadweb.org/viewtopic.php?t=59989&start=10) were i’m interested also, frequently i used in designing of concrete slab on ground (dowel lines). i try reproduced their problem with simplification of models. a simple supported continuous beam with uniform loads, hinged at mid spans of the right beams. without MPC this model is unstable and lead to rigid body motions. offset node coordinates of short beams i made for visually clarification and it be overwrites by keyword during calculatio… --- _[View the full topic](https://prepomax.discourse.group/t/how-to-treat-a-body-as-rigid/1279)._