Stiffness is an important characteristic of production machinery, as it contributes to its ability to precisely maintain the pose between a tool center point with respect to a workpiece under load. For machine tools, it directly affects the geometric dimensions and surface properties of the parts, i.e. how closely the parts match their design drawings. This work presents a novel measurement procedure to measure and identify full translational stiffness matrices of 5-axis machining centers using quasi-static circular trajectories. The measurement procedure consists of inducing quasi-static loads, which vary in magnitude and direction, at the tool center point of the machine tool using the Loaded Double Ball Bar and measuring the displacement with three Linear Variable Differential Transformers while the spindle tracks the circular trajectories inscribed by the movement of the rotary axis. The work outlines and quantifies the main components of the uncertainty budget related to the measurement of the translational stiffness matrices. The measurement procedure is implemented in a case study on a 5-axis machining center. Finally, the manuscript concludes with a discussion on the utility value of the translational stiffness matrix for the design and operation of machine tools as well as the possibility to expand the measurement procedure to a calibration procedure for 5-axis machining centers to analyze the translational and rotational stiffness.

刚度是生产机械的重要特征，因为它有助于精确地保持负载下相对于工件的刀具中心点之间的姿态。对于机床，它直接影响零件的几何尺寸和表面特性，即零件与设计图纸的匹配程度。这项工作提出了一种新颖的测量程序，可以使用准静态圆形轨迹来测量和识别5轴加工中心的全部平移刚度矩阵。测量程序包括感应准静态负载，该准静态负载的大小和方向都不同，在主轴上，使用三根线性可变差动变压器在机床的刀具中心点处测量位移，而主轴则跟踪由旋转轴运动引起的圆形轨迹。这项工作概述并量化了与平移刚度矩阵的测量有关的不确定性预算的主要组成部分。在5轴加工中心的案例研究中执行测量程序。最后，手稿最后讨论了平移刚度矩阵在机床设计和操作中的实用价值，以及将测量程序扩展到用于5轴加工中心的标定程序以分析平移和旋转的可能性。旋转刚度。