Local damping modeling for simulation and optimization of the dynamic behavior of machine tools

机床的动态特性主要决定了机床的性能和加工精度。机床的不平衡动态特性与加工力的相互作用会导致不必要的振动，其后果可能是加工效果不足，刀具磨损增加以及机床损坏。为了在提高机床性能的同时避免这些影响，需要在开发阶段对机床的动态行为进行全面优化。因此，有必要针对各种影响因素建立合适的模型。目前，机床的质量和刚度特性可以得到足够精确的模拟，而机床的不同阻尼效应通常没有合适的模型和参数。为了减少这一赤字，德国研究基金会资助了“机床中的阻尼效应”研究小组。在机床与工业管理研究所（iwb）的子项目“整个机床结构中的阻尼效应仿真”中，研究了机床的机电基本结构，并开发了识别和参数化各种耗散源的阻尼模型的方法。在此基础上，提出了一种考虑质量和刚度特性、线性阻尼、摩擦、控制和运动等多种影响因素的仿真建模方法，并高精度地预测了它们对动力学行为的影响。这为机床动态性能的全面优化开辟了新的可能性。在本项目中，for1087研究组的成果和方法被转移到工业中，并用于优化应用伙伴的加工中心的动态行为。首先，研究了机电一体化基本结构，将阻尼和摩擦模型的识别方法、仿真中的变化和不确定性以及机床结构中各种影响因素的建模方法转移到工业中。在机电一体化结构的基础上，完成整个机床的过渡，进一步识别和分析相关的耗散源。利用这些见解和机床中出现的不确定性的结果，将进行考虑各种影响因素的综合优化。针对定位精度和刀具中心点的动态柔度进行了优化。该程序包括优化潜力的识别、改进措施的确定以及措施的原型实施和评价。根据所得结果，将开发出一种普遍适用的机床动态性能综合优化方法。

The performance and operating accuracy of machine tools is mainly determined by their dynamic behavior. Unbalanced dynamic properties of machine tools in interaction with process forces can result in unwanted vibrations whose consequences can be insufficient processing results, increased tool wear as well as damages to the machine tool. To avoid these effects while improving the performance of machine tools, a comprehensive optimization of the dynamic behavior is required in the development phase. Therefore, appropriate models for the various influencing factors are necessary. State of the art the mass- and stiffness properties can be simulated with sufficient accuracy, whereas often no appropriate models and parameters are available for the different damping effects in machine tools. In order to reduce this deficit, the research group "Damping effects in machine tools" is being funded by the German Research Foundation. Within the subproject "simulation of damping effects in the whole machine tool structure" at the Institute for Machine Tools and Industrial Management (iwb) a mechatronic basic structure of a machine tool was investigated and methods were developed to identify and to parametrize damping models for the various dissipation sources. Based on these results a modeling approach was developed to consider the various influencing factors, such as mass and stiffness properties, linear damping, friction, control and motion in the simulation and to predict their influences on the dynamic behavior with high accuracy. This opens up new possibilities for a comprehensive optimization of the dynamic behavior of machine tools. In this project, the achieved results and methods of the research group FOR 1087 are transferred to industry and used there to optimize the dynamic behavior of a machining center of the application partner. First, a mechatronic basic structure is investigated to transfer the methods for the identification of damping and friction models, for the consideration of variations and uncertainties in the simulation and for the modeling of the various influencing factors in a machine tool structure to industry. Based on the mechatronic structure the transition will be completed on the entire machine tool to identify and analyze further relevant dissipation sources. By using these insights and the results of the occurring uncertainties in the machine tool a comprehensive optimization considering the various influencing factors will be performed. The optimization is carried out with regard to the positioning accuracy and the dynamic compliance at the tool center point. The procedure includes the identification of optimization potential, the determination of improvement measures and the prototypical implementation and evaluation of the measures. From the obtained results, a generally applicable approach for a comprehensive optimization of the dynamic behavior of machine tools will be developed.