Two control strategies for semi-active load path redistribution in a load-bearing structure

In this paper, a two mass oscillator, a translatoric moving mass connected to a rigid beamby a spring-damper system, is used to numerically and experimentally investigate thecapability of load path redistribution due to controlled semi-active guidance elements withfriction brakes. The mathematical friction model will be derived by the LUGREapproach. Therigid beam is embedded on two supports and is initially aligned with evenly distributedloads in beam and supports by the same stiffness condition. With the semi-active auxiliaryguidance elements it is possible to provide additional forces to relieve one of the beam'ssupports. Two control strategies are designed and tested to induce additional forces inthe auxiliary guidance elements to bypass a proportion of loading away from the spring-damper system towards the now kinetic auxiliary guidance elements. The control strate-gies I and II depend on the different control inputs: I beam misalignment and II desiredreaction force ratio in the supports. The beam's misalignment and the supports' reactionforces are calculated numerically and measured experimentally for varying stiffnessparameters of the supports and are compared with and without semi-active auxiliary kine-matic guidance elements. The structure's moving mass is loaded with a force according to astep-function. Thus, undesired misalignment caused by varying stiffness as well as unde-sired load distribution in the structure's supports can be reduced by redistributing loadbetween the supports during operation