Development and application of structural gauge sensitivity methods for vehicle body structure design, assessment, and optimization.

摘要

Reducing the weight of the primary structure in vehicles is an effective way to improve fuel efficiency. The most direct way to achieve such reductions is to decrease the thickness of the sheet metal stock that comprises the majority of a modern vehicle's body. This dissertation presents research on the theory, validation, and application of gauge sensitivity methodologies, a new family of techniques for assessing the effect of thickness changes on automotive structural performance. These methodologies may be adapted to support design optimization decisions at the level of global body architecture (global gauge sensitivity), individual components (component gauge sensitivity), and critical sections or points (local gauge sensitivity). Appropriate calculation algorithms are established for each category of gauge sensitivity assessment, along with techniques and tools supporting the visual rendering and collaborative assessment of the results. The techniques are analytically and experimentally validated. The effect of elastic instability upon the gauge sensitivity of structural components is investigated. Application studies are illustrated through the use of example cases based upon a commercial light-duty truck cab.; Results from gauge sensitivity analysis can yield profound insights into the structural efficiency of the design. Numerical gauge sensitivity indices can provide a qualitative indication of structural efficiency. Gauge sensitivity techniques are particularly well suited to investigate the effect of material substitution or same material down-gauging upon vehicle body structures' noise, vibration, and harshness parameters. Compared with traditional topology optimization algorithms, design decisions from gauge sensitivity analysis are readily realized using practical stamped sheet metal architectures.