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Induction hardening process is widely used to improve fatigue strength of mechanical components that are subjected to cyclic loads in service. The depth of the hardened layer is directed linked with the fatigue and impact strength. So, to improve the mechanical properties in order to preventing fatigue failure in service, it is very important to understand the process and the influence of its parameters. In this paper, a sensitivity study of the influence of some process parameters on the hardness profile of a crankshaft’s crankpin after induction hardening using will be presented. The proposed simulation method include two stages: heating and cooling. In the first stage, the mechanical component, initially at ambient temperature, is heated by electromagnetic induction to a temperature above the steel austenitization. In the second one, the component is cooled by liquid immersion.

Mechanical components, such as parts of internal combustion engine, subject to cyclic loads can be submitted to quenching process in order to improve mechanical properties preventing fatigue failures in service. It is important that such components, due to quenching process, get a high hardness surface layer, increasing the resistance to fatigue, and a tenacious core, with a high capacity of absorbing impacts. In this paper, a multiphysics simulation method of quenching process using Finite Element Method is presented. The proposed simulation method include two stages: heating and cooling. In the first stage, the mechanical component, initially at ambient temperature, is heated by electromagnetic induction to a temperature above the steel austenitization. In the second one, the component is cooled by liquid immersion.

This paper presents a method applied in the development of an optimized transmission rubber mount of a midsize Diesel pickup. The focus of this optimization were to improve the vibration insulation and consequently improve the NVH (Noise and Vibration Harshness) quality of the vehicle. The paper describes the basic mounting design and manufacturing constrains, the simulation modeling basis, inputs required to perform the computational simulation, the experimental method used to extract the center of gravity and rotational inertia of the powertrain and a general mounting tuning strategy. The mounting dynamic simulation results for the optimized version is also presented compared to the original one. In order to quantify the noise and vibration improvements, the internal noise and vibration transmissibility levels were measured and compared in percentile reduction basis to current vehicle levels

A simple evolutionary procedure is proposed for shape and layout optimization of structures with frequency constraints. The structure is modelled with a fine mesh of finite elements plus boundary conditions. It is considered the following hypothesis: small displacements and strains, homogenous and isotropic material. After each eigenvalue solution, a sensitivity number is determined for each element of the structure, so based in this parameter, a number of the elements are removed from the structure. The frequencies of the resulting structure will be shifted towards a desired direction. Several examples are presented to illustrate the options of changing structural frequencies such as: maximizing one or more frequencies simultaneously, maximizing the gap of arbitrary two frequencies

The Noise and Vibration Harshness (NVH) quality is an important customer and benchmark requirement in automotive industry products. The NVH improvement, applied in new projects, is a compromise of cost, performance and time to launch new products. The later trend has been minimized with efforts of computational simulation in the design verification phase. A precise method used for the determination of mass, center of gravity and rotational inertia, allows the engineer to simulate virtual arrangement of mounts before building prototypes. This dynamic simulation of the power train assembly extracts the first six natural frequencies and could be used for mode decoupling. All this systematic evaluations must comply with customers and design requirements. This paper describes the steps of mounting mechanical properties determination and summarizes the main tests used for evaluation of durability, certification and NVH characteristics.

Three vibro-acoustic analysis using Finite Element Method (FEM) is presented. The first analysis is a three-dimensional (3D), interior acoustic, vehicle cabin model, where the modal density and natural frequencies are discussed. The second example is a bi-dimensional (2D) fluid-structure model of the vehicle cabin. In this analysis the main results of the coupled free vibration analysis are presented and discussed. The third example illustrates the use of DtN (Dirichlet-to-Neumann) Map, for exterior acoustic analysis. The DtN Kernel for two dimension problem is presented, and the finite element form is derived. A simple bi-dimensional problem of acoustic radiation from the propulsion system is obtainned.