tvi71it
Guest
Good morning, everyone.
I have a diatribe with my workshop boss on holding a structure I'm designing, so I decided to make a fem calculation to prove that the size I made according to me is correct.
I have attached a pdf where you see the axieme that I should analyze:
a 1040 long aluminum casting (weight about 40 kg) on which a distributed weight will be applied
of about 60 kg of additional details that will then be mounted on this fusion.
the fusion will then have a pin attached to it by coupling with interference and locking nut.
all will be inserted in the support bracket with various bearings (axial and bracing).
to make it short, the case in question is nothing but a zipper that must hold everything to me and allow the aluminum casting to rotate and maintain the system in an acceptable bending.
if all the system remained in the 1-3 mm of bending in the most unfavourable point, that is to the exterminity of the 1040 mm long fusion for me would be a great result.
I therefore did a fem analysis of the fusion alone, inserting a constraint on the hole where the pin is inserted and on the lower contact plane and I had no problem. the result is great as with the forces in play I would have a maximum bending of 0.5 mm.
But now the discussion concerns the fact that if the fusion is sufficiently robust the yield could occur on the steel pin that supports everything, then I made a set with casting, pin and fixed bracket (steel) with relative constraints in order to carry out a total fem calculation and then see if it is true or not that a pin yield will occur.
I simplified it, removing the bearings, nuts, etc... and in the fem I then assigned the slot to the fixed bracket and assigned the contact connection of the pin along the rotation axis and the support plan with the fixed bracket while with the fusion I assigned contact with interference along the axis of the pin and contact in the bar area.
the calculation starts, without errors, but when I arrive at the end I go wrong saying that there is a "pivot too small" and that they probably lack the definitions of connections or are not correct.
honestly I also tried a number of different connections but the calculation always ends in error.
I also tried to put custom constraints, preventing the rotation of the fusion, because I thought the error could result from the fact that the hinge allows the system to rotate (rotation that is negligible in the case in question), but I did not solve.
I thank you therefore in advance for any suggestions.
Hi.
I have a diatribe with my workshop boss on holding a structure I'm designing, so I decided to make a fem calculation to prove that the size I made according to me is correct.
I have attached a pdf where you see the axieme that I should analyze:
a 1040 long aluminum casting (weight about 40 kg) on which a distributed weight will be applied
of about 60 kg of additional details that will then be mounted on this fusion.
the fusion will then have a pin attached to it by coupling with interference and locking nut.
all will be inserted in the support bracket with various bearings (axial and bracing).
to make it short, the case in question is nothing but a zipper that must hold everything to me and allow the aluminum casting to rotate and maintain the system in an acceptable bending.
if all the system remained in the 1-3 mm of bending in the most unfavourable point, that is to the exterminity of the 1040 mm long fusion for me would be a great result.
I therefore did a fem analysis of the fusion alone, inserting a constraint on the hole where the pin is inserted and on the lower contact plane and I had no problem. the result is great as with the forces in play I would have a maximum bending of 0.5 mm.
But now the discussion concerns the fact that if the fusion is sufficiently robust the yield could occur on the steel pin that supports everything, then I made a set with casting, pin and fixed bracket (steel) with relative constraints in order to carry out a total fem calculation and then see if it is true or not that a pin yield will occur.
I simplified it, removing the bearings, nuts, etc... and in the fem I then assigned the slot to the fixed bracket and assigned the contact connection of the pin along the rotation axis and the support plan with the fixed bracket while with the fusion I assigned contact with interference along the axis of the pin and contact in the bar area.
the calculation starts, without errors, but when I arrive at the end I go wrong saying that there is a "pivot too small" and that they probably lack the definitions of connections or are not correct.
honestly I also tried a number of different connections but the calculation always ends in error.
I also tried to put custom constraints, preventing the rotation of the fusion, because I thought the error could result from the fact that the hinge allows the system to rotate (rotation that is negligible in the case in question), but I did not solve.
I thank you therefore in advance for any suggestions.
Hi.