Finite Element Analysis of Dynamic Rigidity of Diesel Engine Housing

Author(s):  
Igor V. Maslov ◽  
Raymond McCafferty ◽  
James P. Rea

Abstract High levels of dynamic loads in a modem diesel engine take place at low frequencies and are connected with the forced vibration of the engine under the action of excitation gas and inertia forces. The lower range of these frequencies are equivalent to the speed of the engine (two stroke) and half engine speed (four stroke). They lead to high stress levels and deformations and often cause internal damage or component failure as well as increasing vibration transmitted to the foundation. One of the most important factors in improving the reliability and durability of engine components and reducing the level of vibration is providing sufficient rigidity for the engine housing. Careful choice of the main dimensions and design parameters will greatly influence engine performance. An engineering approach to the Finite Element analysis of low frequency forced vibration is proposed for the elastic system including crankshaft, engine housing, elastic mounting and foundation. This approach is applied to the analysis of medium speed marine diesel engines with particular attention being paid to the analysis of the rigidity of the engine housing. A solution procedure is proposed to define the loads transmitted from the crankshaft to the main bearings. The procedure takes into account the reciprocal influence of elastic and inertial characteristics of the crankshaft and the engine housing mounting on the elastic foundation, alteration of load amplitudes according to the angular position of the crankshaft, and hydrodynamic behaviour of the lubricating oil film in the contact zone.

2013 ◽  
Vol 313-314 ◽  
pp. 1038-1041
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Chao Li

According to uncertainty of the design parameters for large span truss of installing wave-maker, in order to avoid the waste of materials,the truss is analyzed based on the finite element analysis software ANSYS to find out its weaknesses and various parts of the deformation. On the premise of ensuring the intensity and stiffness, the weight of the truss is reduced by adjusting its sizes and selecting different profiles, so as to achieve the optimization of the truss of installing wave-maker.


1986 ◽  
Vol 30 (4) ◽  
pp. 920-928
Author(s):  
Yoshinobu Maeda ◽  
Masafumi Mori ◽  
Sadami Tsutsumi ◽  
Toshihiro Chinzaka ◽  
Masataka Minoura ◽  
...  

2018 ◽  
Vol 167 ◽  
pp. 02017
Author(s):  
Yunsik Yang ◽  
Euy Sik Jeon ◽  
Dae Ho Park

Several studies have been conducted to prevent neck injury in rear-end collision. The headrest of the seat which suppresses the relative motion of the head and the torso can suppress the extension of the head, thereby alleviating the injury. The active headrest has a mechanism that supports the head by deploying the headrest at the rear-end collision. The spring remains compressed or twisted until a collision signal is generated and the headrest is deployed after the collision signal. Depending on the shape and deployment structure of the spring, a spring design with a high resilience that is acceptable to the headrest is required. In this paper, design parameter of spiral spring suitable for the structure of the developed headrest is selected, prototypes are fabricated, and development parameters such as development time and development distance are checked and optimal design parameters of the spiral spring are derived. The feasibility of the headrest with the designed spiral spring was verified by the finite element analysis.


2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.


Author(s):  
Fakhrizal Azmy Nasruddin ◽  
Muhamad Noor Harun ◽  
Ardiyansyah Syahrom ◽  
Mohammed Rafiq Abdul Kadir ◽  
Abdul Hafidz Omar ◽  
...  

Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Quanbin Ren ◽  
Jie Hong

First, this paper established the seal structural 2D axisymmetric model of a certain Solid Rocket Booster (SRB) and calculated the deformation and stresses at ignition through a large displacement, incompressible, contact finite element analysis. The results show that the maximum contact stress appears at the contact area and the maximum shear stress at groove notch. Then, some typical parameters of the seal structure which might have the impact on the sealing performance, such as the gap breadth, initial compressibility, fillets of the groove notch and bottom, groove width, were analyzed. We can find that the gap breadth and initial compressibility do great contributions to the maximum contact normal stress, and the groove notch and bottom fillets act upon the maximum shear stress obviously. In order to verify the validity of the 2D axisymmetric model, 3D structural finite element analysis of the structure was conducted, and the results indicate that in service, the upper flange is inclined relative to the nether flange, which seems to mean that the gap breadth can not be considered as a constant during the 2D axisymmetric analysis. However further calculations say that if using the minimum gap breadth gotten in 3D analysis as its constant gap value, the above 2D axisymmetric model can rationally take the place of 3D model to analyze the sealing performance. Finally, the failure modes & criteria of the O-ring seals based on the maximum contact normal stress and shear stress were determined to ensure the reliability of this structure.


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