On obtaining machine tool joints stiffness by integrated modal analysis

Contact stiffness of machine tool joints is important but hard to be obtained. An integrated modal analysis method is proposed to obtain the contact stiffness of the joints. The method is composed of finite element method, lumped parameter method, and modal testing. By applying the modal testing data in the finite element and lumped parameter model of the whole machine tool, the contact stiffness of the joints can be obtained. Experiment platform of the joints can be omitted. The contact stiffness of translational guides in a horizontal machining center is obtained as an example. The validity and errors of the method are discussed in the end.