Common method to apply loads on ABAQUS

[TennisGuy543]

I am beginning to run FEA simulations, and I am wondering the most common way to apply loads to a structure in ABAQUS. I see that concentrated loads are the 1st option on ABAQUS, but clearly this will yield an erroneous stress field across the solid since the point load is unrealistic and will therefore induce an unrealistic stress distribution around the area of application . Since I am mainly interested in the stress distribution of the simulations, these concentrated loads will not be acceptable.

This is a pretty fundamental question, but I am wondering what are the common methods to apply loads to a solid on ABAQUS? Clearly it cannot be common to use just concentrated loads. Although, I do not want a load that is as extreme as a point load, I do want the load to be localized to a specific region. I have experimented with other methods such as defining a reference point and using a coupling constraint ("distributed coupling") but I do not know if this is what I should be using.

Obviously the type of load used depends on the system being modeled. So, if it helps, I will briefly describe my model. I'm modeling a robotic arm and I have data on the load that is transmitted through the joint to this arm. So now I'm trying to implement that load in the model. Therefore, the load should be localized, but on as extreme as a concentrated, point force. So the stress field should still show high values at the point where the load is applied, but not has high/extreme as a concentrated force. When I use the coupling constraint, it does not show high values of stress at the region that the load is coupled with, making me think that distributed coupling is not what I want either. Any advice? What about surface traction? Again, I am looking for a common method to apply loads, and looking to understand how engineers "get around" the concentrated load dilemma I described above. Any advice is helpful.

thanks

 

[rstupplebeen]

I typically model 1 solid body more than what I am trying to analyze. So model the part that is causing the loading and apply the load on that part. Often I will only model some of this additional body. I hope this helps.

Rob Stupplebeen

https://sites.google.com/site/robertkstupplebeen/

 

[dimvoly]

I've done coupling to apply what would have been idealized as a point load before. Also it is possible to define an area that the "concentrated" load should be applied over and apply there.

If you can't really idealize your load to a coupling or an area load then you'd want to model the extra part that causes the load.