Attaching Part to Virtual Wall - Examining Bolt Loads

[Inversion]

Hi all,

To begin, first post on Eng-Tips, so sorry if I haven't got anything in the right location or missed out on typical information etc.

Background -
I have no FEA experiance, and I'm trying the hard way to learn FEA in SolidWorks doing some basic modelling. Currently I have a part (grab rail) which I'm trying to attach to a roof, and determine the loads / engineering performance of it and the bolts for different situations. I've included the solidworks file here.

I'm using SolidWorks 2011 Premium, so I have access to Solidworks Simulation.

Problem / What I've done-
Apart from having no idea what I'm doing, I believe I'm running into issues arising from not connecting my foundation bolts into my virtual wall. A quick outline of what I've done / intend -

Load the part in, and create a virtual wall along the top plane, this represents the roof I'm trying to attach the grabrail to. Define foundation bolts at each hole, using the edge of the hole as one reference, the top plane as the other. Apply a 1100N (Min Australian Standard load) vertically downwards along with gravity, and run the model (standard automatic mesh).

What I intend to do is once analyised go Results Adviser > List Pin/Bolt/Bearing Force to help determine bolt sizes needed.

When I try and run the simulation I'm getting the error Status code:9 MATRIX_SINGULAR_OR_INDEFINITE. I believe I'm getting this because my bolts are not attached to the virtual wall, hence there is loose connections floating around, is this assumption correct?

If anyone could give me some advice as to the best way to do this basic modelling it would be greatly appreaciated.

Side note -
Also I've been looking around on a heap of websites for FEA tutorials on solidworks, but there doesn't seem to be much around, especially focusing on connections which I'm having trouble with, might be worthwhile buying a book on it, so can anyone recommend a good Solidworks resource, especially with regards to FEA?


Thanks Eng-Tips!!

 

[ShaggyPE]

I didn't open your part... I am running 2010. Maybe post a screen shot.

Based on your description, I would create split lines around your bolt holes (to represent the washer face) and then "fix" those faces. I would eliminate the bolts altogether. You will be able to get the reactions from the fixed faces. If you wanted the analysis to be more accurate, select the backside of the mounting plate (the one that touches the wall) and create a constraint that only prevents movement in the direction of the wall, but still allows it to pull away and translate.

-Dustin
Professional Engineer
Pretty good with SolidWorks