Junaid, the half model has problems. Look at the quarter model attached here, which has the wood property with plasticity assigned to the block.  The image above is for a steel block without plasticity.  When slicing material in DesignModeler, previously assigned materials get replaced with Structural Steel, because it is assigned as a Default material. That leads to mistakes such as the one above, where I ran with the wrong material. There is a way to remove the Default material so that when slicing is done, the model gets a ? that demands correction, rather than a silent replacement of one material for another.  It is however a good practice to get a model to converge without plasticity before adding plasticity.

Here is how far that same model got with plasticity turned on before convergence failed after 205 iterations.

 *** WARNING ***                         CP =     774.670   TIME= 06:50:22
 Plasticity algorithm did not converge for element number 800 with      
 material number 7.