Application of Lagrange equations in the analysis of slider-crank mechanisms (original) (raw)
Related papers
International Conference on Advanced Computer Theory and Engineering, 4th (ICACTE 2011), 2011
Nissan Z24 is one of the numerous vehicles in Iran. MegaMotor's reports show high rate damaging in the crankshaft and connecting rod of this engine vehicle. It is necessary to carry out a complete research about slider-crank mechanism because of high expensive repairs and replacement of these parts and their reverse effects on the other parts such as cylinder block and piston. Results of initial researches show that an important reason of these parts' damaging is using of downshifting in driving. In this research, we are concerned on the analysis of kinematics and kinetic of slider-crank mechanism of the engine in maximum power, maximum torque and downshifting situation. The influence of different parameters such as engine RPM and downshifting effects were investigated on crankshaft and connecting rod loads. Two methods for analyzing of slider-crank mechanism were used: solving Newton's law and MSC/Adams/Engine software.
The reciprocating engine mechanism is often analysed, since it serves all the demands required for the convenient utilization of natural sources of energy, such as steam, gaseous and liquid fuels, for generation of power. Further, it is widely employed as suitable mechanism for pumps and compressors. In this paper the complete kinematic and combined static and inertia force analysis of a horizontal, single-cylinder, four-stroke internal combustion engine is discussed. The analytical approach is used as it is more accurate and is less time consuming if it is programmed for the computer solution. The data for the analysis of the engine has been taken from the available literature. The present investigation furnishes the complete kinematic history of the driven links and the bearing loads for the complete working cycle of the engine mechanism. The complete force analysis of the engine is simplified by a summation of the static forces and inertia forces ignoring the friction forces which makes the analysis linear. The computer program is prepared in fortran language for both kinematic and dynamic analysis of the engine at the crank interval of 15 0 .
academicjournals.org
Nissan Z24 is one of the numerous vehicles in Iran. MegaMotor's reports show high rate damaging in the crankshaft and connecting rod of this engine vehicle. It is necessary to carry out a complete research about slider-crank mechanism because of high expensive repairs and replacement of these parts and their reverse effects on the other parts such as cylinder block and piston. Results of initial researches show that an important reason of these parts' damaging is using of downshifting in driving. In this research, we are concerned on the analysis of kinematics and kinetic of slider-crank mechanism of the engine in maximum power, maximum torque and downshifting situation. The influence of different parameters such as engine RPM and downshifting effects were investigated on crankshaft and connecting rod loads. Two methods for analyzing of slider-crank mechanism were used: solving Newton's law and MSC/Adams/Engine software.
Analysis of the position and velocity of a slider-crank mechanism
-In the present work, a didactic application is required and implemented to approach the study of the analysis of a crank-slider mechanism's position and velocity. It is based on the mathematical analysis of the closed-loop equation and the vector analysis of the mechanism's velocities. A graphical interface is implemented in the MATLAB GUIDE visual platform. The results are displayed numerically and graphically of the positions' values and angular velocities of the crank-slider mechanism. The program can be a powerful tool in learning mechanism analysis for mechanical engineering students.
Kinematics and Load Formulation of Engine Crank Mechanism
This paper presents the kinematics formulation of an internal combustion engine crank mechanism. The kinematics formulation of the crank mechanism is done using vector loop method and cosine rule are applied to describe the position of the piston. Following the velocity of piston and connecting rod is performed by differentiating the position in terms of the crank angle and connecting rod angle respectively. The acceleration equation with brief form is derived from the velocity in the same principle. Based on the kinematics, the equations of motion of crank mechanism components are formulated for each moving link and platform then, all motion parameters of each component about its crank angle are readily derived. Furthermore the 2D model is provided by using 2D Auto CAD software in order to visualize the system and mathematical algorithm solved by using software MATLAB. The forces acting on the crank mechanism and the torque applied are also formulated based on the angles of the crank and connecting rod.
Dynamic modeling and identification of a slider-crank mechanism
Journal of Sound and Vibration, 2006
In this paper, Hamilton's principle, Lagrange multiplier, geometric constraints and partitioning method are employed to derive the dynamic equations of a slider-crank mechanism driven by a servomotor. The formulation is expressed by only one independent variable and considers the effects of mass, external force and motor electric inputs. Comparing the dynamic responses between the experimental results and numerical simulations, the dynamic modeling gives a wonderful interpretation of a slider-crank mechanism. The parameters of many industrial machines are difficult to obtain if these machines cannot be taken apart. In this paper, a new identification method based on the real-coded genetic algorithm (RGA) is presented to identify the parameters of a slider-crank mechanism. The method promotes the calculation efficiency very much, and is calculated by the real-code without the operations of encoding and decoding. The results of numerical simulations and the experiments prove that the identification method is feasible. Finally, the experimental results by the RGA and the recursive least squares (RLS) are also compared.
Mechanism and Machine Theory, 2014
This paper presents the development of a dynamic model for the slider-crank mechanism with clearance on the piston-pin revolute joint. The equations of motion for this system are obtained by Lagrange's method and the effects related to contact, friction and lubrication at the elements that operate in the clearance are the targets of study. The contact force model used in this work is based on Hertz formulation, considering the inclusion of the dissipative effect associated with the impact between the pin and the piston. The frictional force adopted is based on the Coulomb friction but adapted to the multibody dynamics approach. Such models are verified with the results found in recent literature. The research presents contribution in evaluating the effect introduced by hydrodynamic lubrication in the revolute joint clearance. Two models of hydrodynamic lubrication are investigated: the first model presents a direct solution of low computational cost, the second model results in a numerical solution that consider the effect of the acceleration of the lubricant fluid imposed on the movement of the mechanism. It was observed that the second lubrication model does not guarantee the support of the piston-pin system for hydrodynamic lubrication in the simulated interval of time. Therefore, it is necessary to develop a more realistic model of hydrodynamic and elastohydrodynamic lubrication that is capable of reproducing the behavior of the piston-pin contact.
Kinematic Analysis of compliant slider Crank mechanism
Research Square (Research Square), 2021
This study presents the design and formulation of a kinematic model of a compliant slider-crank micro mechanism and its comparison with the conventional slider-crank mechanism. This work aims with Experimental Analysis of Compliant Slider Crank Micro Mechanism for kinematic performance with a parametric variation. In addition, it also deals with the study of the Mechanical advantage of compliant micro mechanisms. A formulated model is developed using the pseudo-rigid-body model (PRBM). Motion analysis software is used to show the variation in slider displacement for known input link angle. Analysis of compliant mechanism is modeled by PRBM and FEA to analyze deflection. The mechanism is modeled in Adams. The results obtained from Adams are compared with experimentation. The displacements are fairly matches to simulation results. Better displacement as compared to rigid link mechanism can be obtained for smaller angular rotation. Finite element analysis (FEA) is used to show the stress distribution inflexible component for various types of hinges like rectangular cross-section flexible hinges, circular cross-section flexible hinges. Based on stress fatigue analysis is carried for both type joint by experimentally and FEA.
Modelling an Inverted Slider Crank Mechanism considering Kinematic Analysis and Multibody Aspects
2013
In industry, many applications of planar mechanisms such as slider-crank mechanisms (SCM) have been found in thousands of devices. A slider-crank mechanism is widely used in gasoline/diesel engines and quick-return machinery. Research works in analysis of the slider-crank mechanism have been investigated to date due to their significant advantages such as low cost, reduced number of parts, reduced weight and others. A variation of this four- bar linkage is the inverted slide-crank mechanism (ISCM) which is obtained changing the grounded link of the SCM attaching the coupler link to the ground. It kinematic analysis is little studied when compared with the original mechanism (SCM) but the ISCM may represent an important application in the automotive area, like modelling the Macpherson structure suspension. In this way this paper presents the kinematic analysis of an ISCM based in a vector and matrix formulation for future adaptation to modeling the Macpherson struct. The position, ve...
On the Kinematics and Synthesis of the Geared Five-Bar Slider-Crank Mechanism
The geared five-bar mechanism possesses kinematic abilities which qualify it for use in various industrial applications. Small changes to the mechanism topology or dimensions create new designs with different motion characteristics. This paper presents designorientated kinematical insights and mathematical treatments for the embodiment of the mechanism in which the end gear is eccentrically pivoted to a sliding element. For the synthesis effort, a kinematic classification will be introduced and approximate curves will be used to guide the motion of the slider. A gradient-based Levenberg-Marquardt formulation will be employed for the optimisation procedure. Geometric, mobility and dimensional constraints will be utilised together with numerical position equations for the analysis. Two case studies are presented at the end of the paper to highlight the versatility of the mechanism and prove the validity of the presented mathematical model.