Finite element concept modeling of methodologies and software implementation for vehicle assemblies comprised of beam-like structural members.

摘要

Traditional vehicle finite element models, requiring detailed geometric representation, have an extreme degree of complexity making them unsuitable for conceptual design. Concept modeling methodologies are conceptually simple, but operationally difficult to implement because of the structural approximations involved. Current finite element concept modeling methodologies and tools do not permit rapid model generation or modification that is required for conceptual design analysis. This dissertation documents finite element concept modeling methodologies and tools for quickly creating beam components and frame assemblies in vehicle architectures.; A beam component concept modeling methodology has been developed that is consistent with existing conceptual modeling practices. The beam concept modeling methodology divides geometric features into centroidal path geometry, cross section geometry, and component connectivity such as major compliance joints, assembly connections, and component connections. These beam component parametric models are appropriately discretized according to concept modeling practices based on the component's geometry and connectivity; this is unlike existing finite element modeling software; which requires the designer to discretize the model.; A lattice frame assembly concept modeling methodology has been developed for utilization early in the conceptual design stage of a vehicle. The frame concept modeling methodology implements the beam concept modeling methodology to define the beam components comprising the lattice frame assembly. This lattice frame concept modeling methodology is compatible with different types of major compliance joint models.; An interactive vehicle finite element concept modeling software package incorporating the beam and frame concept modeling methodologies has been developed, providing a new finite element modeling tool for automotive designers. This concept modeling software defines vehicle architecture features in a hierarchical manner by specifying major geometric features first and then specifying localized component geometry. The concept modeling software has been rigorously checked for correct geometric representation and finite element modeling connectivity via a test lattice frame assembly incorporating all the major features of the concept modeling software. The test lattice frame assembly finite element model generated by the new concept modeling software was imported into MSC Patran and thoroughly inspected to ensure that correct geometry and connectivity was represented by the concept model. Additionally, the interactive concept modeling software has been verified for implementation for noise, vibration, and harshness (NVH) assessment of lattice frame assemblies.