Hi all,

I have a question about an FEA simulation. Particularly, about the boumndary conditions that need to be applied to run this simulation.

attempt1:

I fixed the right end of the plates and applied loading to the left end. This resulted in stresses go through only the top joint region (W1 in figure attached).

From our understanding, the deformation is got to be symmetric on both the plates. But, when we applied these BCs, it is not smmetric.

attempt-2:

I applied forces on both the ends as shown on top of the attached image. I contrained 2 nodes on exact middle portions of the plates in X direction. Constrained right most and left most edges where force is applied in Y direction.

The deformation looks pratical, but this is not the best case as we are not letting the plate portion that is constrained in Y direction to deform as result of poisson's ratio.

Any thoughts on this simulation will be beneficial.

Also,

are there any symmetry anti-symmetry conditions that I haven't looked into? Please let me know.

Yuan Krishna

By: M. Keikhosravi, RH Oskouei, Payam Soltani, A. Atas, C. Soutis

Purpose - The main aim of this study is to investigate the effect of geometric variables on the stress and strain distributions as well as non-linear deformation behaviour of aluminium alloy 2024-T3 single-lap bolted joints loaded in tension.

Design/methodology/approach - The study has been conducted by using numerical and experimental approaches. In the numerical part, 3-D FE models were generated using ANSYS software for different e/d and W/d ratios in which e and W are variables but the hole diameter (d) is constant. Stress and displacement results for each case have been discussed to better explain the mode of failure. In the experimental part, e/d=3 and W/d=6 ratios were selected as constant and testing specimens were produced accordingly. The aim was to obtain baseline experimental load-strain and load-displacement values for selected specimen geometry coordinated with the numerical analyses.

Findings - The good agreement between the experimental and numerical analysis provided confidence in the numerical methodology used to evaluate the different geometric variables. The results showed that the single-lap bolted plates with optimised W/d and e/d ratios could shift the failure mode from net-tension and shear-out to bearing failure by directing the maximum damaging stresses from the stress concentration region and shear-out planes towards the bearing region, leading to higher failure loads.

Originality/value - - Developing a FE model of single-lap bolted joints with a non-linear material model. - 3D stress analysis as well as non-linear deformation behaviour of bolted plates. - Optimisation of plates’ width (W) and edge distance (e) to control failure modes. - Bigger W/d and e/d ratios shift net-tension and shear-out to bearing failure mode.

Link:

http://www.emeraldinsight.com/journals.htm?articleid=17010368&show=abstract