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Gauge sensitivity indices assess the structural performance of vehicle body architectures when subjected to changes in material thickness as a result of either same material re-gauging or material substitutions. This paper summarises the theory of gauge sensitivity indices and demonstrates the index results through a series of example cases with complex sections and different loading conditions. The results are consistent in showing that gauge sensitivity values are always greater than or equal to unity. It denotes that while low gauge sensitivity values imply a perfect structure with near-uniform internal load distribution, large values correspond to the progressive development of an internal load distribution that becomes increasingly non-uniform. The work concludes with validation case studies illustrating application of gauge sensitivity indices for assessing structural stiffness of a light-duty truck cab.

Hydraulic drives are inherently heavy, and when such systems are combined with an internal combustion engine in a hybrid powertrain, the need to reduce mass becomes acute. This paper presents finite element models supporting weight reduction studies on a Hydraulic Power Assist (HPA) unit designed for use in a light-duty truck. Specifically, we determined the modal parameters and frequency response characteristics associated with critical structural components used to mount the HPA unit. Stress distributions, deformations, and strain energy distributions were computed for excitations arising from both vertical accelerations and harmonic forces. Results were used to evaluate weight-reducing design modifications.

Reducing the weight of the primary structure in vehicles is an effective way to improve fuel efficiency and kinematic performance. The most direct approach to achieve such reductions is to decrease the thickness, or gauge, of the vehicle sheet metal stock. This article describes the development of numerical indices for assessing the sensitivity of vehicle body structure architectures to changes in noise, vibration and harshness (NVH) characteristics associated with thickness changes resulting from either same material down-gauging or material substitutions. A rigorous mathematical analysis is used to derive relationships between the indices and NVH parameters, such as structural stiffness and fundamental natural frequencies of critical deformation modes. The derivation also suggests algorithms for computational implementation. The work concludes with a series of validation case studies illustrating application and interpretation of the gauge sensitivity indices.