Introduction of physical simulation in the hottest

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Introduction to physical simulation in NC machining

physical simulation is mainly mechanical simulation, which studies the physical state of the workpiece during cutting. Only by thoroughly studying the mechanism of physical simulation can we truly meet the purpose of virtual manufacturing, that is, the real mapping of the actual machining process on the computer

The main contents of physical simulation include cutting force simulation, machining error simulation, chip generation process simulation, tool offset, deformation and wear simulation, and vibration and temperature simulation of NC cutting machine tools

cutting force is a basic factor in the simulation of the expanding scope of the material industry, and is usually considered as a function of the material removal rate per unit time. Based on this, the approximate force condition of the tool can be obtained more stably, and then the specific distribution of the cutting force on the tool can be obtained by further processing with the finite element method

the factors that affect the workpiece processing error are mainly the position error of the fixed surface hardness increasing with the increase of the amount of filler. Other influencing factors also include the machine tool motion accuracy error, tool size error, spindle movement, guide rail deformation, clamping force, tool, part thermal deformation and elastic deformation error, and the error caused by the processing method. According to the influence degree of these errors, the total error of machining accuracy can be obtained by adding the concept of weight and fuzzy comprehensive evaluation

the real-time simulation of cutting generation process is the main link of "seamless connection" and synchronous display between virtual NC and actual machining. The generation, coiling, breaking and shape of cutting are affected by many factors, such as the geometry of the tool, cutting fluid, workpiece and tool material, as well as the stress of the tool and workpiece. The research shows that when the cutting thickness is very small, the cutting thickness has a linear relationship with the cutting force

tool wear and offset will greatly affect the machining error and product quality of NC machining. The experimental data show that the tool wear volume per unit feed distance and unit area is related to cutting temperature and compressive stress. The tool is simplified as a cantilever beam, and its main force is the cutting force on the tool head. After calculation, the offset of the tool can be obtained

machining temperature is an important factor affecting the machining properties of tools and workpieces. The machining processes of grinding and turning are continuous and easy to be described by formulas, while milling is intermittent cutting, which needs to be described with some modifications

the vibration that may be caused by power will also affect the machining surface accuracy of the workpiece. The real-time simulation of machine tool vibration can provide the basis to avoid or reduce vibration and reasonably select machining conditions. There are two significant factors in the influence of machine tool vibration: (1) the dynamic parameters of machine tool, workpiece and tool and the system that changes with the position and direction of cutting force vector. (2) The dynamic behavior of machining materials, tool shapes and materials, cutting conditions, tool wear types and wear quantities related to cutting forces

the friction between chip and tool surface affects many factors, such as chip shape, system temperature and so on. Friction changes from the time when the cutting edge of the tool enters the workpiece to the time when it leaves the workpiece. The size of cutting friction and the system temperature affect each other, so it is necessary to coordinate these factors to obtain the optimal machining effect. The impact property of the composite material prepared by surfacing at room temperature is improved to 1.9 times of the original

these factors are only some factors that will affect the quality of the final workpiece in NC machining, and these factors will also affect each other, and some will also become factors that need to be directly considered in the design. Therefore, when considering these factors comprehensively, they should coordinate with each other to obtain the best machining results

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