Prediction of noise radiation on cylinder head

Noise radiation analysis of an engine's component can be implemented through several methods such as theoretical calculations, experimental and simulation. The use of finite element method integrated with boundary element method based computer software in engineering field has shown growing interest due to shorter duration of analysis and easy to use. In this analysis, observation of vibration characteristic for two-stroke engine's cylinder head is carried out. Initially, finite elements are used to create the engine's cylinder head model. Data gained from modal analysis is used for prediction of noise radiation from cylinder head surfaces. At this stage, acoustic boundary element model is preferred instead of finite element model. Finally, the results of this study can be used for further analysis in designing of two-stroke gasoline engine

Influence of Fiber Volume Fraction on the Tensile Properties and Dynamic Characteristics of Coconut Fiber Reinforced Composite

The utilization of coconut fibers as reinforcement in polymer composites has been increased significantly due to their low cost and high specific mechanical properties. In this paper, the mechanical properties and dynamic characteristics of a proposed combined polymer composite which consist of a polyester matrix and coconut fibers are determined. The influence of fibers volume fraction (%) is also evaluated and composites with volumetric amounts of coconut fiber up to 15% are fabricated. In this work, the tensile test was carried out to determine the strength of material, while modal testing was used to obtain the dynamic characteristics of the composite material. Results were found that the strength of the composites tends to decrease with the amount of fiber, which indicates ineffective stress transfer between the fiber and matrix. The dynamic characteristic of composite was also having a same effect where the natural frequency decreased with increase of coconut fiber volume. However the damping ratio was found to be increased by the incorporation of fiber. When higher fiber content of 15% was used, the damping ratio shows the maximum value for almost all the frequency mode. It was observed that the effects of reinforcing polyester matrix with coconut fibers lead the composites more flexible and easy to deform due to high strain values and low stiffness. In fact, it may also be used to reduce high resonant effect

Investigation on Dynamics Characteristic of Multilayer Steel Plate Impacted by Projectile

The paper describes a work focused on the process of perforation of multilayer advanced high strength steel (AHSS). A numerical investigation has been carried out to analyze in details the perforation process subjected to normal impact by different nose shapes of projectiles. The perforation process has been simulated by the application of 3D analysis using IMPACT dynamic FE program suite. The comparison on failure modes depending on the projectile nose shape have been studied and evaluated. An appropriate constitutive relation was applied to describe the material behaviour of the multilayer target plate. The study covered different failure modes of perforated advanced high strength steel (AHSS) sheet according to different level of impact velocity ranging from 22 m/s to 78 m/s. The blunt projectile impact towards multilayer target plate leads to generation of plug formation and fragmentation while hemispherical projectile impact shows almost similar petals formation between first, second and third layer

Prediction of noise radiation on cylinder head

Noise radiation analysis of an engine's component can be implemented through several methods such as theoretical calculations, experimental and simulation. The use of finite element method integrated with boundary element method based computer software in engineering field has shown growing interest due to shorter duration of analysis and easy to use. In this analysis, observation of vibration characteristic for two-stroke engine's cylinder head is carried out. Initially, finite elements are used to create the engine's cylinder head model. Data gained from modal analysis is used for prediction of noise radiation from cylinder head surfaces. At this stage, acoustic boundary element model is preferred instead of finite element model. Finally, the results of this study can be used for further analysis in designing of two-stroke gasoline engine