Study on non-torque load decoupling of conjugate loading test rig based on stiffness matrix method

The six-degree-of-freedom load mechanical test of the wind turbine nacelle drive chain using the test rig can fully and effectively simulate the complex external wind, wave, current and soil environmental loads on the unit. The conjugate loading method commonly used in the test rig only contains 6 loading force sources, which has strong coupling and can apply non-torque five-degree-of-freedom loads at multiple points and positions on the loading axis. In order to solve the problem of how to accurately apply non-torque five-degree-of-freedom loads using 6 loading force sources in the conjugate loading method, this paper regards the loading system as a fixed-beam model and divides it into 7 units. Based on the stiffness matrix method, the non-torque five-degree-of-freedom load is decoupled to obtain the input force loads of the 6 loading points, and then the displacement response of each node can be obtained. The force analysis model of the loading system is further established using Solidworks software, and 4 sets of loading force sequences are used to illustrate that larger loads such asF1 andF2 are beneficial to the stability of the loading system, and the correctness of the stiffness matrix method is verified, providing a new method for load decoupling.