Abstract

Based on the torque‐axial load coupling properties of twisted cord, a new unipolar composite theory is developed. Overall, the full complement of the so‐called micropolar stress/moment‐strain/rotation gradient coupling is accommodated. This includes the handling of the skew‐symmetric stress to relative matrix wind‐up interaction which is a central feature of continuous twisted cord‐reinforced composites. To establish various interaction effects, both analytical and finite element models of unit cell behavior are employed. Due to the mixed tensor‐vector properties of the constitutive formulation, a specially anisotropic polar formulation is developed. To illustrate the millimeter level importance of polarity, i.e., millipolarity, the results of several case study problems are also presented for cord‐reinforced elastomeric composites. These include both square and alternating (triangular) packing morphologies. To generalize the results, the investigations include a wide range of packing densities.

Abstract

Over the past ten years the Finite Element Analysis (FEA) has been increasingly integrated into the tire design process. The FEA has been used to study the general tire behavior, to perform parameter studies, and to do comparative analyses. To decrease the tire development cycle, the FEA is now being used as a replacement for certain tire tests. This requires the accuracy of the FEA results to be within those test limits. This paper investigates some of the known modeling techniques and their impact on accuracy. Some of the issues are the use of shell elements, assumptions for boundary conditions, and global/local analysis approaches. Finally, the use of new generation supercomputers, massively parallel processing systems (MPP), is discussed.

Abstract

Requirements to reduce the external noise emitted by automobiles are continuously evolving because of the increasing number of vehicles circulating in urban areas and the growing demand for a better quality of life.

In this paper, an updated review will be presented of different approaches to noise reduction in the two main world car markets, Europe and the United States, showing today's legal requirements and future trends. In this context, the role of the tire will be analyzed by describing the mechanisms through which it generates external noise, its importance with respect to other vehicle noise sources, and the possibilities that exist to reduce its contribution.