Hi all
I have been using simulation for some time with the static module, on some of my studies I would like to know the residual displacement (or deformation) after unloading.
Example : I load a guardrail with a force x on the handrail then I remove this force and I would like to have the displacement in mm of the "residual" handrail.
Does the "non-linear" module allow this function? If so, how can it be implemented?
Friendly
Phil.
Hello
To do this study, you need Simulation Premium.
After the implementation is a bit complex...
Hello
The example of the guardrail is perhaps poorly chosen because, in this case, it is necessary to remain in the elastic range and, consequently, the residual deflection is equal to 0 after unloading. As a general rule, we always try not to laminate a mechanical element except possibly in an accidental case.
On the other hand, a nonlinear calculation often gives very approximate results compared to an experiment. 1 because the actual yield strength is often much higher than the norm. 2 because nonlinear models use bilinear approximations of behavior, which is not necessarily very representative near the elastic limit.
To be carried out with caution.
Hello and thank you for your answers,
To take my example on the guardrail, the standard requires the application of a force called "ultimate limit state" (NF E 85-015 chapter 7.3.2.2), between two uprights and in the axis of the upright, in both cases, the residual deflection must be less than 10% of the deflection measured under the load at the ultimate limit state.
Secondly, I am looking with my manager if we don't have a "premium" version of solidworks.
On my workstation I have a "standard" version but equipped with the "simulation" module.
Friendly
Philippe
Hello
Be careful, you don't need a SolidWorks Premium (which integrates static simulation) but a Premium Simulation.
@+
Indeed, I understand the question better.
However, this type of test, specific to the NF version (it does not exist in the ISO version, which is much more commonly used) is almost never carried out. Indeed, the rest of the paragraph also indicates that the test must then be continued until the guardrail breaks. Even the inspection bodies generally accept that the nominal load test is sufficient.
Afterwards, if you want to make a quick approximation from your linear calculation, the residual deflection (if the elastic limit is exceeded) is about equal to the maximum deflection - the deflection to the elastic limit.
Since the calculation is done in linear, the deflection at the elastic limit is deducible from the total deflection by a simple rule of 3.
I repeat, however, that this theoretical result must be taken with caution because the tests are much more favourable. So don't panic if the calculation gives a result of 15% for example.
After checking we have a solidworks simulation premium license.
So I have to be able to carry out my study, but how can I use the "non-linear" module in a few words?
Friendly
Philippe
P.S.: Thank you Chamade for your explanation, which allows me to have an approximation of the arrow.
I don't have the tool so I won't really be able to help you with the practice.
In general, it's not much different. You need to define a nonlinear material (bi-linear in general) and choose a type of nonlinear analysis as well.
Since nonlinear calculation is usually done in an iterative way, it is necessary to check that it has "converged" to ensure that the result is correct.