aansys joint of lines and arcs

[clark]

there is a problem . when i make the frame of chassis using key points and lines. lines do not join properly at single point. like if there are 4 lines meeting at a point then 2 of them are in contact while the other two are not sitting at the required point. though this is visible only after very high zoom. but on applying force joint breaks... what can i do

[clark]

there is a problem . when i make the frame of chassis using key points and lines. lines do not join properly at single point. like if there are 4 lines meeting at a point then 2 of them are in contact while the other two are not sitting at the required point. though this is visible only after very high zoom. but on applying force joint breaks... what can i do

[Jordan Yeomans]

What CAD program are you using?

Solidworks has a feature called structural members which can be used to model a space frame.

There is a tutorial here - http://www.youtube.com/watch?v=nN_00HcEPls&fmt=22

If you are using an alternative CAD program im sure there are similar features which may help.

[SNasello]

Try modelling the frame using only nodes and elements instead of keypoints and lines. How are you doing the input file for ansys? with a text file or GUI? are you using ansys classic? Ansys has an excellent help file if you know what you are looking for.

There are only a few commands you need to model a spaceframe. Look at the help file and learn how to input nodes, and read the element type guide. Beam 4 is probably what you want to use for straight members and there is an analogous one for curved members. I never had much luck using keypoints and lines, but the node-element approach always seemed to work fine.

The process you want to fallow is:
-set element properties (cross section, bending moment of inertia, material type)
-define nodes
-define elements connecting nodes (similar to defining lines)
-apply loads and constrains at desired nodes
-calculate model

hope this helps

[BMH]

I use the Beam 188 element rather than the Beam 4 element. I also use the MPC 184 rigid link element to simulate the the engine in the frame.

[clark]

thanx every one. hey jordon, im using ansys for analysis. i input all the keypoints whose co ordinates are taken from solidworks. since ansys is more reliable than solidworks. i use gui method.there is an element table command in ansys for calculating von mises stress. how can we use it to plot stress in individual member.