Stress Of Crankshaft Research Articles

Optimized design of silicone oil torsional damper for diesel generator

Abstract Due to the high cylinder pressure and high-performance requirements, the silicone oil damper of an inline six-cylinder diesel generator needs to be optimized to reduce the crankshaft stress. The centralized mass method was used to simplify the crankshaft system. A multi-body dynamic model was established, and the crankshaft stress and torsional vibration amplitude were simulated. The results show that the excessive shear stress at generator crank pin 5 is due to the resonance between the first-order intrinsic frequency of the shaft system and the 3rd harmonic torsional vibration. The shear stress was analyzed for different damper thicknesses and stiffnesses, and it was found that the shear stress at crank pin 5 was minimized when the damper thickness was 60 mm and the torsional stiffness was 250,000 N·m/rad. The torsional amplitudes at different speeds and frequencies were measured in the bench test, and the results were consistent with the calculations. The designed silicone oil torsional damper meets the requirements of the 2000-hour bench test.

Finite Element Analysis of Crankshaft Stress and Vibration in Internal Combustion Engines Using ANSYS

Finite Element Analysis of Crankshaft Stress and Vibration in Internal Combustion Engines Using ANSYS

Crankshaft Stress Telemetry Device and Its Low Power Strategy

In view of the fact that the crankshaft of an internal combustion engine lacks the support of measured stress data due to the closed working environment, a real-time stress test device for crankshaft and its low power strategy were studied. An embedded telemetry technology is used to solve the system miniaturization and low-power strategy. The integrated circuit chip is used to realize the miniaturization design, and a specialized power management scheme is designed to realize the low-power strategy. The actual test shows that the device can run continuously and stably under the environment of high temperature and oil pollution inside the crankcase and can record the stress curve of the crankshaft and transmit it to the remote computer in real time, which realizes the data visualization on the computer. The designed low-power strategy can help the device complete a single test period, and the device has higher promotion value and practical significance.

Dynamic characteristics analysis of long stroke reciprocating pump combined crank-linkage with rack-pinion mechanism

Drilling pump is the heart of drilling rig, its core structure is crank-linkage mechanism. However, the drilling pump is criticized for its short stroke and high stroke frequency. Aiming at these defects, a long stroke reciprocating (LSR) pump combined the crank-linkage with a rack-pinion mechanism is proposed, and its dynamic and flow characteristics are researched. The results reveal that the stroke of the LSR pump is extended twice when the crank radius stays the same. The stroke frequency and flow pulsation rate are lowered under the same rated power. A new multi-fulcrum crankshaft is designed to extend its fatigue life, and the reaction forces of each fulcrum are solved by simulation. The influence of the fulcrums position on the crankshaft modal frequency is further investigated. The flexible characteristics of the multi-fulcrum crankshaft are studied by rigid-flexible coupled analysis. The results show that more fulcrums can effectively reduce the stress of crankshaft, and the maximum stress of the multi-fulcrum crankshaft is only 178.6 MPa. The modal frequency of the multi-fulcrum crankshaft is increased due to more fulcrums, which proved its stiffness and stability are improved. The fatigue life of the multi-fulcrum crankshaft is predicted to reach 30,000 h by finite element analysis. This study would provide a theoretical basis for further development of the LSR pump.

Analysis of dynamic fatigue characteristics of critical parts of highly strengthened single cylinder diesel engine

In this paper, the strength analysis and fatigue life calculation of multi-component coupling of crankshaft, connecting rod and engine body of highly strengthened single cylinder diesel engine are carried out. The stress of crankshaft, connecting rod and engine body in two working cycles is calculated by multi-component coupling transient dynamics, and the strength is analyzed based on the third strength theory firstly; Then, the accuracy of the transient calculation results is verified by the strength experiment of the crankshaft and connecting rod reduced scale model and the calculation of the static stress of the body; Finally, according to the stress fatigue life calculation method, the fatigue life of crankshaft, connecting rod and engine body is calculated. The maximum stress of crankshaft, connecting rod and body is less than the yield limit of corresponding materials; The fatigue life calculation results show that the damage accumulation of the engine body is very little, which meets the design requirements of infinite life. The damage accumulation of the crankshaft at the fillet of the main journal and the connecting rod at the side of the rod is 32005.6 hours and 102841.7 hours respectively, which meeting the design requirements of 20000 hours.

Failure analysis of ductile iron crankshaft in compact pickup truck diesel engine

The crankshaft is one of the structural components of the engine that converts the linear motion of the piston into rotational motion. In this study, the failure analysis of spheroidal graphite cast iron (SGCI) crankshafts of compact pickup truck diesel engine was investigated that premature failure occurred in the web-crankpin fillet zone of all four crankpins. A series of experiments including chemical composition, mechanical properties, hardness, and tensile tests were performed. Optical microscope (OM) and scanning electron microscopes (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) were used to investigate the microstructure, defects, fracture surface, and failure cause. To estimate the crankshaft stress field under cyclic bending combined with steady torsion, a nonlinear three-dimensional stress analysis model was used. Fractography showed that the failure is a type of transient low cycle fatigue and includes three zones of crack initiation, fatigue crack propagation, and fast final fracture. Also, hardness and microstructure results revealed that there is no hardened surface layer on both the crankpin and the main journal (>600 HV0.1 proposed standard). In addition, the microstructural characteristics showed that the material nodularity used in the failed crankshafts is within the acceptable minimum range (>80% nodularity). Besides, numerical stress analysis showed that the highest stress is in the web-crankpin fillet zone, which is in good agreement with the experimental field measurements. Finally, recommendations have been provided to ensure long fatigue life and prevent premature failure.

Finite Element Analyses of Automobile Crankshaft Using ANSYS

Finite Element Method (FEM) of failure analysis was developed on automobile crankshaft, to determine the stress distribution and the fatigue life, by using ANSYS software. Further, an analytical analysis is applied, Measure the crankshaft stress life. A study was performed on some of the Honda CR-V engine components, specifically are crankshaft, the connecting rod, and the piston. Upon the finite element analysis, it was found that the fillet areas of the crankshaft are the most critical locations where high stresses were generated in these areas. Moreover, with/without considering torsional force acting on the crankshaft does not appear to have any major effects on the stress experience by the crankshaft. In addition, the location where the crack initiated, and fatigue failure starts is located at one of the crankpin journal fillet areas. Indeed, the crankshaft critical areas are mostly affected by uniaxial stress. Moreover, the prediction of the crankshaft fatigue life by using the strain-life theory gives the overall most conservative fatigue life results.

Failure Analysis of Ductile Iron Crankshaft in Four-Cylinder Diesel Engine

Spheroidal graphite cast iron is widely used in automobile crankshafts due to features such as high strength, high toughness, good machinability, low cost, and ductility. The purpose of this paper is first to analyze the fatigue failure in fractured truck crankshafts between 400,000 and 1,350,000 km and then to predict the stress field under the influence of the mechanical loads caused by gas combustion. Several experimental studies including chemical composition, material strength, hardness, and microstructure are performed to evaluate the failure analysis. A nonlinear three-dimensional stress analysis model by the elastic–plastic finite element method is used to estimate the crankshaft stress field under cyclic bending combined with steady torsion. Failure analysis showed that the fracture surface consisted of three zones: fatigue crack initiation, fatigue crack propagation, and static fracture; therefore, the failure is in fatigue. Also, the microstructure results showed that the crankshaft nodularity is about 70%, which crankshaft structures are usually acceptable greater than 80% of nodularity. Besides, hardness gradient showed that the crankshaft crankpin had no hardened surface layer. Finally, numerical stress analysis indicated that the highest stress is in the crankpin–web fillet zone that it is in good agreement with those obtained in the experimental field measurements.

Reduction of Crankshaft Stress By Using of the Torsional Vibration Damper

Abstract This paper deals with the stress analysis of crankshaft of a 4- cylinder internal combustion engine. The crankshaft is during its operation subjected to static and dynamic load. High frequency dynamic cyclic loading can lead to material fatigue and eventually fracture. To reduce this dynamic loading a new type of torsional vibration damper built in the crankshaft counterweight will be analyzed with the use of numerical simulation. After defining boundary conditions and applying loads, Von Mises stress analysis will be performed using the finite element method.

Fatigue analysis of high performance race engines

This paper presents a multidiscipline dynamic simulation tool for fatigue testing. A non-linear finite element formulation embedding control system modeling is augmented to include fatigue analysis based on a mathematical representation of virtual brittle lacquer and strain rosettes. A new efficient method for rosette strain calculations based on super node displacements are applied and presented. These features are used to predict the hot spots and durability of a high performance race engine. Real physical testing is performed to capture all engine properties influencing the crank shaft stress distribution. The results predict the most critical failure modes during racing applications as well as the life in terms of drag laps before failure.

Systematical Analysis Method for the Mechanical Behaviors of Crankshaft-Bearing System

Various mechanical behaviors will happen at the same time when an engine operates. Based on this concept, in this paper, a systematical analysis method is presented to analyze the multiple mechanical behaviors (tribology, dynamics, stiffness, and strength) of the crankshaft-bearing system in an engine. By this method, the analyses of the tribology of bearing, the dynamics of crankshaft-bearing system and the dynamic stress of crankshaft can be accomplished simultaneously. For example, the effect of the journal misalignment of crankshaft and the elastic deformation of bearing bush on the dynamics of crankshaft-bearing system, the tribological performances of main bearings and the dynamic stress of crankshaft are analyzed emphatically. The results show that the journal misalignment of crankshaft and the elastic deformation of bearing bush have remarkable effect on the tribological performances of main bearings and the dynamic stress of crankshaft, but have little effect on the dynamics of crankshaft-bearing system.

Static structural analysis of crankshaft for single cylinder camless engine

The crankshaft is a complex component, and as such, the influence of its geometric parameters on stresses seen under service loads is not well understood. The objectives of this work is to investigate the effects of a wide range of geometric parameters on stresses in crankshafts, to find correlation between results and to formulate simple methods of predicting peak stress levels: It is intended to achieve this by use of fatigue method. Analyses are carried out in 2D and 3D, making use of symmetry as far as possible. Variations in stresses are plotted over a wide range for each of the parameters. The analysis methods give accurate results for stress analysis of crankshafts and offer several advantages over traditional experimental techniques; they are ideally suited to parametric analyses, can be carried out relatively quickly, results are repeatable because boundary conditions can be exactly defined, and the cost of analysis is significantly reduced.The analysis is carried out in ANSYS for crankshaft along for single cylinder camless engine.

Force Analysis of Engine Crankshaft Based on Finite Element Method

In this paper, the working states of the engine crankshaft stress by detail force analysis of engine crankshaft and 3D modeling by finite element method, understanding the stresses and deformation of the engine crankshaft, improve the analysis provides a theoretical basis for structure design; has an important significance for optimization, guide the crank shaft.

Dynamic Crankshaft Strength Calculation of Diesel Engine Using Simulation Techniques

Crankshaft is one of the most important parts in diesel engine. The fatigue failure and fracture of crankshaft may lead to damage to the other parts, even some accidents. Recently with the increasing requirement of engine power and engine reliability, the investigation of the crankshaft strength becomes more important. Since during the engine work process, the extremely complicated force are loaded on the crankshaft and different vibration caused by torque, bending, etc., the crankshaft may create the resonance and appended dynamic stress in the working frequency range, which will be easy to bring about the bending and torsion damage after short work period. In this paper, the traditional algorithm on the basis of MATLAB/SIMULINK software is used to carry out the dynamic calculation and analysis for a certain type of diesel engine crankshaft. The crankshaft stress state and its variation are analyzed, and the results of the bending moment, torsion versus crank angle are obtained. Finally, the fatigue strength of crankshaft is checked and the safety factor is calculated to verify the crankshaft reliability.

Dynamic method of investigating stress concentrators of the YMZ-238 engine crankshaft considering surface hardening plastic deformation

The article presents an approach to analyzing the stress-strain state of the YMZ-238 crankshaft after surface roller hardening. The approach is based on dynamic modeling of the stress-strain state of the crankshaft stress concentrators. The real-time modeling of roller hardening makes it possible to get a diagram of residual stresses occurring in the strengthened surface layer of the fillets. The next step is the analysis of the parts stress-strain state applying the boundary conditions corresponding to the operating conditions of the engine. The dynamic research of the stress-strain state of the crankshaft makes it possible to analyze the manufacturing technology and identify the origin of cracks in stress concentrators taking into account the improvement of fatigue resistance resulting from hardening treatment.

Torsional Vibration Analysis for Large-Scale Reciprocating Compressor Crankshaft

This paper presents a new method which combined multi-body dynamics theory and finite element technology to calculate transient stress of the crankshaft of the large-scale reciprocating compressor. On the basis of multi-body dynamics theory, the kinematical simulation of the crankshaft, the connecting rod, the piston and other components were performed, and thus to get the vibration modal of the crankshaft. So we can judge whether the crankshafts torsional resonance will happen, as well as get the real loads on the crankshaft when it worked. Then the transient stress of the crankshaft can be calculated using finite element technology. Comparing to traditional stress calculating methods, this new method not only considers the variable inertia which caused by reciprocating masss movement, but also can calculate the integrated vibration stress of crankshaft in three directions, including torsion, lateral and axial. Therefore, this method can describe dynamic characteristics of the crankshaft more accurately and more entirely.

Dynamic simulation and stress analysis for reciprocating compressor crankshaft

With the continuous trend toward high speed and large size, the reciprocating compressor crankshaft faces more serious potential threat of crack due to vibration. Therefore, early stress analysis of the crankshaft must be done thoroughly in the design stage. This article introduces a method, which combines flexible body dynamic and finite element analysis to calculate stress of the crankshaft. In this method, the load variation with time is obtained by flexible body dynamics simulation of crank and connecting rod mechanism. After that loads are loaded on finite element model of the crankshaft, and then the stress of the crankshaft is calculated in time domain. This stress can be utilized to do fatigue analysis and predict the life of crankshaft. Using this method, stress of a practical crankshaft, belonging to 6M51 reciprocating compressor, is calculated. The result showed that the maximum von Mises stress is 158 MPa, and the estimated life, which was calculated by Palmgren–Miner linear damage accumulation theory, is 2.0230e + 007 hours.

Three-Dimensional FEM Analysis for a Kind of Engine Crankshaft

By using SolidWorks2010 software 3d entity modeling for the engine crankshaft of the developed tobacco harvest machine was built, and Ansys system combining working conditions to crankshaft with Ansys finite element method was imported. Then the crankshaft's stress result figure in four conditions was got, the stress concentration area was found, comparing and the analysis the the working conditions of the results, thus the basis theory for the engine of the crankshaft structure optimization design and research was provided.

The Performance Research of Automotive Crankshaft Based on ANSYS Workbench Collaborative Platform

Crankshaft is widely used in the automotive industry, its quality has a direct impact on engine and vehicle performance. This paper the finite element analysis of crankshaft is discussed by using four different loads based on ANSYS workbench collaborative platform, thus the distribution of stress and strain is obtained and the relationships between arc radius and crankshaft stress is studied by changing the value of arc knuckle radius between the connecting rod journal and the crank at the junction of the transition, lastly the intrinsic mode of the crankshaft is analyzed. The results for the crankshaft provide a theoretical basis for designers and reference.

Design and FEM Analysis for Crankshaft in Truck Mounted Petroleum Compressor

Crankshaft in truck mounted petroleum compressor is constrained by space concerns, design is difficult. In this paper, primary structure design parameters are extracted from the crankshaft design process, and crankshaft stress distribution is calculated under ANSYS, providing a reference for compressor optimization. It is useful to guide the design.