Modifying the range of angles or aspect ratios has a minimal effect on the quality of the mesh. In most cases, you should not modify the default values. You can also enter the maximum skew angle for quadrilateral and tetrahedral elements and the maximum taper for quadrilateral elements. If you chose to allow the Optimization module to adjust mesh quality, you can use the table to specify the range of angles (quadrilateral and triangular elements) or the range of aspect ratios (tetrahedral elements) that define an element that is considered good quality. If you allow the Optimization module to stop the optimization because the Abaqus element quality criteria is violated, it will be easier for you to troubleshoot the optimization and determine why it failed. If Abaqus stops the analysis prematurely, no results are available to the Optimization module, and the optimization ends prematurely. It is possible that the Optimization module will generate a poor quality mesh that will not allow the Abaqus analysis to complete successfully, especially as the number of design cycles increases. If you toggled on Report solver quality criteria violation, you can choose to stop the optimization process if Abaqus encounters elements of poor quality. Toggle on Report solver quality criteria violation to report elements that Abaqus considers to be of poor quality. Toggle on Report poor quality elements to generate a list of elements that fall outside the ranges defined in the element quality table. Toggle off Target mesh quality to deactivate the algorithm that calculates the element quality. If you are unable to obtain a satisfactory mesh quality, even with a convergence level of High, you should consider reducing the amount of displacement during the shape optimization by reducing the Growth scale factor and the Shrink scale factor, as described in Configuring advanced options. Even though it is computationally expensive, you may want to select a higher convergence level if your mesh contains a large number of tetrahedral elements otherwise, the mesh quality may not be acceptable. You should select a higher convergence level only after you have determined the mesh quality is not satisfactory. In most cases you should accept the default setting of Low. Toggle on Target mesh quality, and select a setting ( Low, Medium, or High).
In the optimization task editor for a shape optimization, click the Mesh Smoothing Quality tab.