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Virtual design validation of an air induction system (AIS) requires a proper finite element (FE) assembly model for various simulation based design tasks. The effect of the urethane air filter seal within an AIS assembly, however, still poses a technical challenge to the modeling of structural dynamic behaviors of the AIS product. In this paper, a filter seal model and its modeling approach for AIS assemblies are introduced, by utilizing the feature finite elements and empiric test data. A bushing element is used to model the unique nonlinear stiffness and damping properties of the urethane seal, as a function of seal orientation, preloading, temperature and excitation frequency, which are quantified based on the test data and empiric formula. Point mobility is used to character dynamic behaviors of an AIS structure under given loadings, as a transfer function in frequency domain.

Durability of a product is related to three major factors, the load, structure and material. The durability performance of an automotive product is, therefore, not only depended on the structure configuration, but also on the road load dynamic characteristics (profiles and frequency spectrum), and the material fatigue properties as well. Due to the dynamic nature of vehicle loads, one of the major technical challenges, to the durability design optimization of automotive products, is how to define a set of representative road loads, for fidelity and efficiency, based on the measured proving ground durability data of huge size. This paper presents a procedure of processing the proving ground road loads, for vehicle durability design and optimization of automotive products, based on the statistical characteristics evaluation and fatigue damage equivalency techniques.

An accelerated test procedure has been developed at Visteon to reduce the component durability test time, while meeting the reliability requirements. The method and procedure are presented in this paper with application examples to wiper motor bearing retainers. The new test speed, load level, and test duration of the accelerated test are derived by employing the CAE durability and reliability techniques. The accelerated test speed is determined based on the dynamic characteristics of the test specimen-fixture-machine system, using the CAE finite element analysis method. The increased test load level is obtained based on CAE dynamic stress simulation, material fatigue model, and durability damage equivalence. The reduced test duration (or number of test cycles) is determined based on CAE equivalent fatigue damage technique and modified from the reliability requirement parameters, such as reliability target, confidence level, and sample size.

It is well known that product durability is related to three major factors, the structure, load and material. That is, the durability performance of an automotive product is not only depended on the structure configuration, but also related to the load dynamic characteristics (such as, profiles and frequency spectrum), and the material fatigue properties as well. Due to the fact that the automotive vehicle loads are dynamic in nature, one of the major technical challenges to the product durability design is how to quantify the fatigue damage sensitivity. This paper presents a procedure of automotive structural design for durability performance based on the structural dynamic simulation and fatigue damage sensitivity techniques. A methodology for calculating the fatigue damage sensitivity is introduced.

This paper presents a CAE virtual test procedure for automotive engine mount systems, which evaluates NVH and durability performance of an engine suspension design. Engine mount systems are virtually tested in terms of noise and vibration response characteristics, mount structural strength and fatigue durability, under the defined engine load conditions. The proposed procedure incorporates several CAE modeling and simulation technologies, including the definition of engine test loading environment, the modeling of nonlinear rubber bushings for their stiffness and damping properties, the frequency domain dynamic simulation, and fatigue damage prediction technologies. First, the test engine load specifications are defined from the measured engine vibration raw data with respect to engine speeds, and the engine speed duty cycle statistics.

Both NVH and durability performance of automotive products are mainly related to their structural frequency characteristics, such as their resonant frequencies, normal modes, stiffness and damping, and transfer function properties. During the automotive product development, product design validation test loads for NVH and durability are, therefore, often specified in the frequency domain, in terms of either swept sinusoidal vibration or random vibration in power spectral density function. This paper presents a procedure of CAE virtual design validation tests for durability evaluation due to the frequency domain vibration test loads. A set of frequency domain simulation techniques and durability evaluation methodologies, for material fatigue damage due to either random or sinusoidal vibration loads, are introduced as well.

Plastic air induction system (AIS) has been widely used in vehicle powertrain applications for reduced weight, cost, and improved engine performance. Physical design validation (DV) tests of an AIS, as to meet durability and reliability requirements, are usually conducted by employing the frequency domain vibration tests, either sine sweep or random vibration excitations, with a temperature cycling range typically from -40°C to 120°C. It is well known that under high vibration loading and large temperature range, the plastic components of the AIS demonstrate much higher nonlinear response behaviors as compared with metal products. In order to implement a virtual test for plastic AIS products, a practical procedure to model a nonlinear system and to simulate the frequency response of the system, is crucial. The challenge is to model the plastic AIS assembly as a function of loads and temperatures, and to evaluate the dynamic response and fatigue life in frequency domain as well.

In this paper, an analytical procedure for prediction of shell radiated noise of air induction systems (AIS) due to engine acoustic excitation, without a prototype and physical measurement, is presented. A set of modeling and simulation techniques are introduced to address the challenges to the analytical radiated noise prediction of AIS products. A filter seal model is developed to simulate the unique nonlinear stiffness and damping properties of air cleaner boxes. A finite element model (FEM) of the AIS assembly is established by incorporating the AIS structure, the proposed filter seal model and its acoustic cavity model. The coupled acoustic-structural FEM of the AIS assembly is then employed to compute the velocity frequency response of the AIS structure with respect to the air-borne acoustic excitations.

Visteon has developed a CAE procedure to qualify instrument panel (IP) products under the vehicle key life test environments, by employing a set of CAE simulation and durability techniques. The virtual key life test method simulates the same structural configuration and the proving ground road loads as in the physical test. A representative dynamic road load profile model is constructed based on the vehicle proving ground field data. The dynamic stress simulation is realized by employing the finite element transient analysis. The durability evaluation is based on the dynamic stress results and the material fatigue properties of each component. The procedure has helped the IP engineering team to identify and correct potential durability problems at earlier design stage without a prototype. It has shown that the CAE virtual key life test procedure provides a way to speed up IP product development, to minimize prototypes and costs.