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In spite of the changes in vehicle performance, one of the current challenges is to get components applicable to different vehicles with no changes in the project. Simulations made with specific numerical programs enable this process of unifying components, for different platforms, to be applied to the exhaust system. The projects proposed, based on the results obtained with the simulation programs, were tested experimentally. It was proven that the results of the simulation proposals correlated to the experimental results. This ultimately provided simplification to the project, with gains in logistics and productivity. Besides the technological process involved, possibilities to reduce costs can also be considered.

Acoustic components are used in automotive exhaust systems to minimize the noise from the engine and, consequently, to offer more comfort and sound quality to the consumer. Thus, analytical, experimental and numerical studies of these acoustic filters become important in engineering. In this regard, the aim of this article is to report the development of an experimental bench for acoustic transmission loss based on the transfer matrix method for application in studies of automotive mufflers and resonators. The validation of the method was performed by comparing the results obtained experimentally to predictions of numerical simulations and analytical calculations carried out in an acoustic expansion chamber and in a Helmholtz resonator. After the validation, experiments with different automotive mufflers having diverse internal configurations were carried out in order to study the different attenuation frequencies of the components.

The durability certification is one of the critical paths of a mass production vehicle project. For structural components, the development and the execution of experimental tests supported by finite element method (FEM) became mandatory for implementation time reduction, especially when on-board diagnoses (OBD) legislation turns even small cracks in severe structural failures. This job aims to show a simulation method of structural efforts in an exhaust system on a test bench. The exhaust pipe is previously analyzed with FEM and the critical points are instrumented with strain gage in vehicles. The strains are measured and its values reproduced in a dynamometer bench using a shaker with adjustable amplitudes. Therefore, difficulties to reproduce temperature and strain were overcome and the test shows repeatability. The variation of shaker device amplitude makes it possible to define the life cycle curve of the part.

The selection of the materials to a specific application in the Industry has a great importance for the success of a project, particularly when there exists the union of two or more parts, by a weld fillet. The mixture of different classes and chemical compositions in stainless steels in high temperature applications can cause the nucleation and early propagation of fatigue failures, decreasing the life of the product. The present article shows a case study, on which the adequation of the chemical and physical compatibility, and consequent thermal dilation in a specific structure, increased the durability of the component. The study consists of chemical analysis, macroscopic and microscopic evaluation tests on variated materials combination on welding fillets.

Acoustics, in a broad sense, is an essential product attribute in the automotive industry, therefore, it is relevant to study and compare theoretical and numerical predictions to experimental acoustic measurements, key elements of many acoustic development processes. The numerical methods used in the industry for acoustic predictions are widely used for exhaust system optimization. However, the numerical and theoretical predictions very often differ from experimental results, due to modeling simplifications, temperature variations (which have high influence on speed of sound), manufacturing variations in prototype parts among others. This article aims to demonstrate the relevant steps for acoustics development applied in automotive exhaust systems and present a comparative study between experimental tests and computer simulations results for each process. The exhaust system chosen for this development was intended for a popular car 4-cylinder 1.0-liter engine.