How to do this (right support) on a cylindrical face? I have a longboard, one truck is a fixed hinge, and I would like to make the other truck a rotational slider. Thanks!

@goengineer

6 жыл бұрын

Hi bkkrdbkstn, To make a similar Pin or Roller/Slider fixture on a cylinder it would require two split line definitions; one to make an axial edge down the bottom of the cylinder and one to make a circumferential edges around the circumference of the cylinder near the ends of the cylinder. The intersection of these model edges will create the vertex that either the Pin or Roller/Slider fixture would be applied to. This would inevitably create an unstable model though. For this specific setup for a cylinder it would require the use of a half model, cut axially vertically, with a symmetry fixture applied to make a fully stable model like the techniques used in this video: kb.goengineer.com/go/default.aspx?kbID=14059

How can I remove stress from the supports ?

@goengineer

6 жыл бұрын

Hi noname90, It is possible that the stresses in the supports on this analysis are perfectly valid stresses. It would definitely be realistic that the load distributed across the top of the beam would ground out in the two point fixtures on the bottom of the beam. The distributed force then becomes two concentrated reaction forces and would cause point stresses in the fixtures. Some convergence testing of the results would be recommended. You may wish to look at using h-adaptive iteration of the results like this: kb.goengineer.com/go/default.aspx?kbID=14214

The fixation is totally wrong. As a result you will get wrong displacement and stress in the middle of the beam comparably to manual calculation. The lines that are fixed should intersect the neutral axis of lengthwise section and be placed on the ends of the beam. Any point of bottom plane must have possibility to move along the beam and vertically.

@tmtan1303

2 жыл бұрын

That's what the beam theory lecture made hinge on a straight beam as a line. What does the matter if I make a wooden plate as shown in this video with two rollers attached to it at the bottom then I stand at the middle?

@dmitriymalenkov9979

2 жыл бұрын

@@tmtan1303 Well, I have to admit that I was wrong. I calculated the stress in the middle of the bottom face of the beam in 3 ways : 1 - using fixation as shown on the video 2 - using different fixation that gives correct results 3 - calculated the stress manually For my dimensions and force I got the following results: 1. 412 MPa 2. 413 MPa 3. 416.7 MPa Convergence is very good. My apologies to the GoEngineer team!

@UserUser-pr2ls

2 жыл бұрын

@@dmitriymalenkov9979 Добрый день. Скажите что за "different fixation that gives correct results"?