Modeling of a lathe bed using the method of topological optimization

Abstract

Based on the drawings of a typical construction of the bed of the 16K20 lathe, its 3D model was made. Its study was carried out using force factors. A conceptually new lightweight design of the bed was obtained by means of the Autodesk shape generator module, taking into account the power factors. The research method is a topological optimization of the model under study, which allows obtaining a new conceptual model of the lathe bed with acceptable stiffness and significant material savings. Materials for the manufacture of beds were studied and evaluated. As for the use of materials for the manufacture of the lathe bed, cast iron remains the most optimal material in terms of "mechanical characteristics - price - weight". We see its advantages in the balance of characteristics. The modeling data allows to see the internal stresses of the structure, deflection of the part, and displacement due to the applied force factors. The images of the 3D model demonstrate this clearly. The disadvantage of the shape generator is the inability to study a 3D model made of several materials, so the research was conducted for a homogeneous model. The undoubted advantage of a shape generator based on the finite element method is that it clearly shows the areas of the structure that are ballast and do not perceive any load. This allows the research engineer to optimize the design, taking into account the recommendations of the shape generator, accumulated knowledge and experience. Thus, we obtained a new conceptual model of the lathe bed for further theoretical experiments. The analytical calculation of the bed structure was also carried out using the above methodology. The values of lathe bed deflection and its influence on the deflection of the part were obtained. To expand the study, calculations were performed for parts of different lengths, namely 1000 mm and 1400 mm. This paper does not reflect the dynamic state of machining of parts in dynamics, but it allows to assess the weaknesses of the structure and identify trends in strengthening or lightening of individual areas. In particular, the use of topological optimization enables the estimation of possible material savings, which is relevant in the context of decarbonization of production and trends in sustainable development.