Hello I want to do a static study and a fatigue study The forces applied to an aluminum rack. are the weights of the parts to be transported) to resize the structure. I used the bars (body) directly to apply the forces and not the surfaces I would like to have the behavior of the structure that we use the blades of a forklift 'I have separated the surfaces where the blades will be in contact with the structure but I can't define the force at this area. Can I combine the types of selections (nodes/bodies with surfaces) or do I have to change the behavior of the members to large bodies?
1°) In simulation, we do not speak of surface in the sense of an object in the surface area. I say this just to avoid any ambiguity
1 bis) I always work in full volume. This greatly simplifies the problems and interpretations of deformations. One of our colleagues (whom I salute) also works in volume
2°) If I understand the problem correctly, you have a frame which, once loaded, is lifted by a forklift. As a result, under the weight of the different objects, the frame must deform more or less. With the problem of loads that are heterogeneous (flanged tube with taps, IPN, etc.)
3°) The fact that you have declared the direction of gravity only makes sense if you also have a gravitational charge or masses at a distance.
I think that to get out of this, you have to simplify the model by transforming all the objects hung or transported into loads via sketches and force connectors.
I personally think that built will receive different charges distributed according to the operator's logic and therefore variable according to the day. This is why it is better to define loads arbitrarily floor by floor at the center where there is the max bending, which should be more than enough.
For the pressure on the areas where there will be the forks, just put the connectors that fit well on delimited areas.
I try to simulate the building (part) and not the assembly file, I attached the image just to give a framework to the study I am trying to carry out. The frame will carry only the attached parts, it will be laid on the ground and moved by forklift. The behavior of the spikes does not interest me, the deformation of the frame when using the trolley that interests me. I applied forces equivalent to the weight of the parts to be transported on the load-bearing members of the latter or I had trouble with the forces is to apply the forces of the trolley blades, do I have to define these areas as fixed support? or a force equivalent to the total weight .
Oops, I don't think I understood. What is your version of SW (I only have the 2022) Could you make a pack and go of your rack with the simulation results. In the indicated choice you want a ZIP file
With the file it will be easier to continue the discussion
I would do as @Zozo_mp : study in volume to avoid problems with the beam/shell connection. For your different loads you can use 'remote weights' (quite painful to set up because you need the coordinates of the different centers of gravity).
Nb: be careful to take safety coeffs because your trolley will ultimately work in dynamic (shocks when placing or taking) and not just in pure static.
Hello I attach the two STEP and Parasolid files with the desired forces. I'm a beginner on the simulation side so I don't know how to do everything. ^^’
Ben! Uh Your file is full of interference. It is impossible to do a simulation in these conditions. Please remove the interference in the tubes and repost your model in PARASOLID format
As indicated by @Zozo_mp, it is probably the interference between bodies that is the cause of a refusal of the calculation during the simulation. Luckily, a simple removal of material from the tubes is enough to correct the problem.
A static simulation is then possible. One of the four supports on the fork of the trolley is defined as a fixed imposed displacement, the other three as imposed movements of the plane support type, so as to guarantee the balance of the structure. The model is included in SW 2021 version.
Given the very low maximum stress, one may wonder if a fatigue study is of any interest...
Hello Thank you for your answers @Zozo_mp and @m.blt I understand that interference must be eliminated, Static and fatigue simulation to resize the structure and use other profiles.
@Farouk For the static simulation ok, although certainly already quite solid in the current state. As for changing the profile to have thinner, it is only of interest if you produce several per day (and even then because the weight differential is peanuts on the cost of the frame.
For the fatigue study, I agree with @m.blt because personally I only do this type of study for parts subject to vibrations or load displacements within the frame (a suspended load that oscillates for example)
Thank you for your help @Zozo_mp@m.blt I was thinking of switching the 40x4 square tube to 30x2 or 3 square tube For the fatigue study, the parts on the frame are for decoration and they are often rented, I don't know the rental frequency and therefore the frequency of handling and handling. I try to reduce the cost of manufacturing as much as possible. Thank you again for your help. Kind regards
In my opinion, a 40x4 or 30x2 or 3 tube doesn't change much. The price will be more related to the manufacture than to the material. (fab time) And welding aluminum 2 can sometimes be more difficult than 4 (and therefore longer) The 2mm can pierce more easily, deform more...
