Autodesk nastran stress analysis software analyzes linear and nonlinear stress, dynamics and heat transfer characteristics of structures and mechanical components. Difference between rbe2 and rbe3 elements, using a simple beam example. This section includes a description of all known errors and general limitations in all releases of msc. What is the difference between rbe2 and rbe3 in fea. What is the difference between connecting elements with different dofs with mpc constraints and cerig command. Nx nastran connection elements rbe2, rbe3 and cbush and. Nx nastran is an enhanced proprietary version developed and. The difference between rbe2 and rbe3 elements, using a simple. The name is similar, but there is a fundamental difference between them.
Slide 7 common geometrybased rigid elements rbar rigid bar with six dof at each end. It describes some of their main uses, as well as the key differences between rbe2s and rbe3s. Rbe2 transmits the displacements and rbe3 transmits the loads mpc forces i made 2 videos that show. Hence, care needs to be taken when defining an rbe3 element. Fea white papers and presentations produced by the predictive engineering staff on topics such as fracture mechanics and fea, small connection elements, linear and nonlinear buckling analysis, rbe and modeling composites. As far as i understand the difference between pbarl and pbeaml is that in pbeaml you may specify a varying section through the element. It can also be used transition elements types shells to solids, beams to solids, etc. Where applicable, you can see countryspecific product information, offers, and. Part of the autodesk solution for digital prototyping.
The common filenames for the programs installer are nastran. Basic difference between rbe2 and rbe3 given in the posts that followed. The resulting forces andor displacements can be verified by the provided formulas. The relative position of grids connected by the element does not change during the analysis. I am looking for a method changing the coordinate system of rbe2 or rbe3 elements. Rbe3 is used for load distribution or a flexible connection. Nx nastran is a finite element fe solver for stress, vibration, buckling, structural failure, heat transfer, acoustics and aeroelasticity analyses manufacturers as well as engineering suppliers in aerospace, automotive, electronics, heavy machinery, medical device, and other industries have relied on nx nastran software for their critical engineering computing needs for over 40 years. Lesson 16 rigid element analysis with rbe2 mscnastran 120 exercise workbook version 70 mscpatran 7. This document is the concise guide to nastran rbe2 and rbe3 rigid elements. What is the basic diffrence between rbe2 and rbe3 in fea.
In a rbe2, grid 1 is the independent and grids 2n are dependent. Now, i am wondering if coordinate change is possible or not. Below is the nastran description of rbe2 in nastran user guide. Unlike the rbar and rbe2 elements, the rbe3 doesnt add. Why do we need to have two options if it can be achieved using one option. Rbe2, rbe3, rbody, and when to use which one respectively. Other than that, i thought the cbar and cbeam elements referencing the pbarl or pbeaml behave the same for example if i have elements with fixed section through the element, i thought using cbeam or pbeam would give the same results. Plasticity creep contact material models sol 402 difference composites nonlinear mechanism sol 401 difference multiphysics couplings planned. Many uses but do not use them unless you understand them. This software and related documentation are proprietary to siemens product lifecycle. Integer 0 required gn identification number of grid point to which all six. Normal modes rigid element analysis with rbe2 and conm2.
Also, if you look at the rbe3 documentation, you will see that nastran provides a manual method to rearrange this equation using the optional um input. Defines a rigid body whose independent degrees of freedom are specified at a single grid point and whose dependent degrees of freedom are specified at an arbitrary number of grid points. Most people can figure out the load distribution for the rbe2 element but that for the rbe3 defies simple logic if you dont know the mathematical formulation. Create a tube model with a rigid end, define mass concentrations and perform modal analysis. A simple central load is applied, and blas demonstrates the differences between the rigid. The commercial use of nastran has helped to analyze the behavior of elastic structures of any size, shape, or purpose. Convert rbe3 to rbe dof 123456 this tool will convert multiple rbe3 elements into rbe2s with dof 123456 this tool is compatible with femap version 10. Nastran is the nasa structural analysis system, a finite element analysis program fea completed in the early 1970s. Defines the motion at a reference grid point as the weighted average of the motions at a set of other grid points. Rbarand rbe2 elements artificially add stiffness by constraining the system to follow a one toone linear displacement andor rotational relationship between the connected nodes. Convert rbe3s to rbe2 dof123 this tool will convert multiple rbe3 elements into rbe2s with dof 123 this tool is compatible with femap version 10. Comparison of some commercial software systems for. Moment load force load april 2011 nt f th rbe3 lttildth tx tz model file. Linear static rigid element analysis with rbe2 and conm2.
Field definition type default eid element identification number. Which fea software is mostly used in the industry, and why. There is no difference between plane strain and plane stress. Both elements look the same, in that they have a single node connected to one or usually multiple other nodes. I would expect zero thermal expansion of the model. Rbe2 vs rbe3 vs rbody altair hypermesh altair forum. Integer 0 required refgrid reference grid point identification number. Rbe2 elements also distribute the force and moment equally among all connected nodes, irrespective of. Your web browser must have javascript enabled in order for this application to display correctly. Please keep this in mind when using previously constructed apis with femap v2020. Recent versions are sometimes referred to by the cd id as follows.
Linear static and normal nodes analysis using mscnastran and mscpatran. Nx nastran basic is the core subset of nx nastran software and includes a robust suite of linear statics, normal modes, buckling analyses, heat transfer and basic nonlinear capabilities. Fea engineering white papers predictive engineering. Nastran was released to the public in 1971 by nasas office of technology utilization. They are both variations of an mpc multi point constraint. Nastran has been released under the nasa open source agreement version 1. Unfortunately, there is no manual option for changing an rbe2, you must use autompc or change your model. Small connection elements rbe2, rbe3, cbush and how useful for fea modeling. In the other side, the rbe3 element on femap with nx nastran is a. What is the basic diffrence between rbe2 and rbe3 in fea element with proper practical application. Model this two ways in one database using rbe2 and rbe3 elements. Rbar and rbe2 elements artificially add stiffness by constraining the system to follow a one to one linear displacement andor rotational relationship between the connected nodes.
If recovering the abaqus results in nastran is a theme, you can calculate mass normalized modes, export these and use them in nastran or any other software using e. Page 4 20180508 siemens plm software nx nastran multistep nonlinear sol 401 and 402 core capability multistep solutions. When i run the model in msc nastran there is a conflict between the aset containing the rbe3 dependent node. Nx nastran fe solver analysis modules fea software. Mpc can be used to connect many nodes at one surfaceline to many nodes at surfaceline. In short, rbe2 is a rigid element which adds stiffness. Rbe2 transmits the displacements and rbe3 transmits the loads.
Rbe3 is an interpolation element used to distribute mass and loads. In the other side, the rbe3 element on femap with nx nastran is a powerful tool for distributing applied loads and mass in a model. The resulting forces andor displacements can be verified by the. The motion at the dependent node is a weighted average of the motion at the independent nodes. This can happen if there are insufficient independent dofs to properly resolve the applied loads and moments for static equilibrium. Another limitation when choosing between rbe2 vs rbe3 elements is that rbe3 is capable of producing unwanted mechanisms. Share your knowledge, ask questions, and explore popular nastran topics.
Making efficient connections with rbe2 rbe3 constraint. Nx nastran basic can play a key role in your virtual product development process by providing the most widely. Comparing rbe2 vs rbe3 elements, rbe3 on the other had is not a rigid element so to speak. A comparison is presented between rbe2 and rbe3 formulations. Rbe2 rigid body with independent dof at one grid, and dependent dof at an arbitrary number of grids. This tool was originally designed by siemens product lifecycle management software. Can someone explain the difference between these 1d elements i. We are in the process of updating our apis to be compatible with v2020.
Integer 0 required refc component numbers at the reference grid point. Cerig can be used to connect one master to many slaves. So, im just sharing with you first of all, these two elements are not exactly rigid elements per say. Rbe2 and rbe3 are basically rigid elements that are use to connect mesh sets together. In a rbe3, grid 1 is the dependent and grids 2n are independent. The displacement of grid 1 is the weighted average of the displacements of grids 2n. Create a filter to exclude all elements except rbe2 and rbe3 elements.