Vibration strength design for the node module of the Russian segment of the International Space Station

RSC Energia has developed a new module for the Russian Segment of the International Space Station. It is a pressurized spherical habitable compartment with six docking ports. The module was given the name Node Module. The paper presents the complete cycle of solving engineering problems for assuring vibration strength in the course of the module development. It discusses how the finite-element model of the structure was generated. It provides the model configuration, structure and dimensions. It points out specific features of the products structure and their reflection in the finite-element model. The computations were performed in the ANSYS software package. The paper presents the work with the model in the course of both calculations and developmental testing. Test results are presented. An actual structural failure is described. The paper cites the errors that caused the failure and corrective measures that were taken. It provides comparative results of calculations and measurements during tests. It shows the ways and methods of updating the model and adjusting it based on the test results. The dynamic finite-element model updated on the basis of the test results can be used as a means of monitoring the mechanical durability of the module primary structures in the course of its in-orbit operation. It also provides a reliable tool for analyzing the module structure in off-nominal situations.