عنوان مقاله [English]
Machine tool static deflection due to the machining forces and thus the displacement of tool tip is the most important factor in reducing the dimensional accuracy of workpiece. Also, overlap of the operation frequency range with the machine natural frequencies causes an undesirable resonance phenomenon. Since the operating frequency range is lower than the first natural frequency, increasing the first natural frequency of milling machine and reducing the displacement of tool tip is a desirable modification that can be achieved by optimizing the wall thickness distribution and the internal stiffeners layout of column. This paper suggests a new method for the optimization of stiffeners layout for plate/ shell structures. In each step of optimization, by establishing a loop of relationship between MATLAB and ABAQUS software and based on the sensitivity analysis, the most effective stiffeners on optimizing the objective function are added to design space. After optimizing the wall thickness distribution of the column using the ABAQUS software size optimization module, the suggested method is used to optimize the internal stiffeners layout. Ultimately, without increasing the column weight, the maximum displacement of machine tool is reduced by 6.9% and the first natural frequency is improved by 16.5%.