Development of Reduced Order Thermomechanical Model Using Floating Frame of Reference Formulation

In this paper, a reduced order thermomechanical model based on the Craig-Bampton component mode synthesis method is extended to the floating frame of reference formulation for the thermomechanical analysis of flexible multibody systems. To this end, coupled structural and thermal equations of finite element models are partitioned in terms of the internal and interface coordinates, each of which consists of the structural and thermal coordinates. Both deformation including the thermal effect and temperature in the internal region are then defined by a linear combination of the thermomechanical fixed-interface normal modes and thermomechanical constraint modes to account for structural and thermal modes associated with external forces and heat sources applied to the system. The final form of equations include equations of motion associated with a flexible body that incorporates thermal deformation and the reduced order heat equations that describe the transient change in the temperature over the flexible body. For this reason, the inertia coupling of the reference motion and the thermal deformation is automatically considered using the floating frame of reference formulation. Both equations are integrated forward in time simultaneously using general multibody dynamics computer algorithms to account for the coupled structural and thermal behavior of flexible multibody systems. Several numerical examples are presented to demonstrate the use of the numerical procedure developed in this study.