On the Modeling of Flexible-Link Planar Mechanisms: Experimental Validation of an Accurate Dynamic Model

2004 ◽  
Vol 126 (2) ◽  
pp. 365-375 ◽  
Author(s):  
Alessandro Gasparetto

The experimental validation of an accurate dynamic model of flexible multi-body planar mechanisms is presented in this paper. The proposed mathematical model, which is valid for whatever planar mechanism with any number of flexible links, accounts for the geometric and inertial nonlinearities of the mechanism, and considers coupling effects among rigid-body and elastic motion as well. In order to experimentally validate the dynamic model, a flexible five-bar planar linkage actuated by two electric motors is employed as a test case. The experimentally measured deformations and accelerations of the flexible links are compared with the numerical results obtained by simulating the system dynamic behavior through the mathematical model. It turns out that the experimental results are in good agreement with the numerical ones, thus proving that the dynamical model proposed is very effective in the difficult task of accurately representing the dynamic behavior of flexible mechanisms.

Author(s):  
R. Caracciolo ◽  
A. Gasparetto ◽  
A. Trevisani

Abstract This paper presents an experimental validation of a finite element approach for the dynamic analysis of flexible multi-body planar mechanisms. The mathematical model employed accounts for mechanism geometric and inertial non-linearities and considers coupling effects among rigid-body and elastic motion. A flexible five-bar linkage actuated by two electric motors is employed as a test case. Experimentally determined link absolute deformations are compared with the numerical results obtained simulating the system dynamic behavior through the mathematical model. The experimental and numerical results are in good agreement especially after the very first transient period.


2014 ◽  
Vol 986-987 ◽  
pp. 810-813
Author(s):  
Ying Li Shao

The exhaust noise, which falls into low-frequency noise, is the dominant noise source of a diesel engines and tractors. The traditional exhaust silencers, which are normally constructed by combination of expansion chamber, and perforated pipe or perforated board, are with high exhaust resistance, but poor noise reduction especially for the low-frequency band noise. For this reason, a new theory of exhaust muffler of diesel engine based on counter-phase counteracts has been proposed. The mathematical model and the corresponding experimental validation for the new exhaust muffler based on this theory were performed.


2002 ◽  
Vol 128 (3) ◽  
pp. 506-517 ◽  
Author(s):  
S. M. Camporeale ◽  
B. Fortunato ◽  
M. Mastrovito

A high-fidelity real-time simulation code based on a lumped, nonlinear representation of gas turbine components is presented. The code is a general-purpose simulation software environment useful for setting up and testing control equipments. The mathematical model and the numerical procedure are specially developed in order to efficiently solve the set of algebraic and ordinary differential equations that describe the dynamic behavior of gas turbine engines. For high-fidelity purposes, the mathematical model takes into account the actual composition of the working gases and the variation of the specific heats with the temperature, including a stage-by-stage model of the air-cooled expansion. The paper presents the model and the adopted solver procedure. The code, developed in Matlab-Simulink using an object-oriented approach, is flexible and can be easily adapted to any kind of plant configuration. Simulation tests of the transients after load rejection have been carried out for a single-shaft heavy-duty gas turbine and a double-shaft aero-derivative industrial engine. Time plots of the main variables that describe the gas turbine dynamic behavior are shown and the results regarding the computational time per time step are discussed.


Author(s):  
S. M. Camporeale ◽  
B. Fortunato ◽  
M. Mastrovito

A novel high-fidelity real-time simulation code based on a lumped, non-linear representation of gas turbine components is presented. The aim of the work is to develop a general-purpose simulation code useful for setting up and testing control equipments. The mathematical model and the numerical procedure are specially developed in order to efficiently solve the set of algebraic and ordinary differential equations that describe the dynamic behavior of the gas turbine engine. The paper presents the model and the adopted solver procedure. The code, developed in Matlab-Simulink using an object-oriented approach, is flexible and can be easily adapted to any kind of plant configuration. For high-fidelity purposes, the mathematical model takes into account the actual composition of the working gases and the variation of the specific heats with the temperature, including a stage-by-stage model of the air-cooled expansion. Simulation tests of the transients after load rejection have been carried out for a single-shaft heavy-duty gas turbine and a double-shaft industrial engine. Time plots of the main variables that describe the gas turbine dynamic behavior are shown and the results regarding the computational time per time step are discussed.


2020 ◽  
Vol 59 (37) ◽  
pp. 16136-16145
Author(s):  
Jaime Dueñas Moreno ◽  
Tatyana Poznyak ◽  
Julia Liliana Rodríguez ◽  
Isaac Chairez ◽  
Hector J. Dorantes-Rosales

1993 ◽  
Vol 115 (1) ◽  
pp. 70-77 ◽  
Author(s):  
R. J. Chang ◽  
T. C. Jiang

The dynamic equation of a robotic manipulator with joint irregularities is formulated and employed for the prediction of the positioning accuracy and precision of a robotic manipulator in high-speed operation. The mathematical model is derived by incorporating a dynamic model of irregular joints in an ideal robotic equation and employing the Lagrangian formulation. The joint irregularity is modelled as an elastic sliding pair which consists of a journal with an irregular surface sliding on the surface of an elastic bearing. By employing Gaussian linearization methods, the operational accuracy and precision of the robotic manipulator are obtained from mean and covariance propagation equations of the robotic system. The operation of a single-arm robotic manipulator with joint irregularities is investigated for demonstrating the applications of the present techniques.


2012 ◽  
Vol 271-272 ◽  
pp. 1178-1182
Author(s):  
Juan Juan Xing

The paper uses the object-oriented modeling method to analysis the hydraulic AGC system and the operation mechanism about a strip mill. It discusses the Coulomb force and roll eccentricity which usually were ignored on rolling process. And improves the mathematical model that reflect the actual AGC system. By simulation, we compared it with the actual rolling process and verified the correction of the mathematical model. And, it will make the good foundation for on-the-spot practical application.


2013 ◽  
Vol 475-476 ◽  
pp. 1375-1381
Author(s):  
Jian Rui Duan ◽  
Jin Yao ◽  
Hua Li

In order to calculate the friction work of lock-up clutch, which come from the lock-up process of hydraulic torque converter, this article established a simplified dynamic model of the engine and hydraulic torque converter , according to the route of power transmission and the rule of moment balance. And then the mathematical model of the lock-up process was deduced. This article reached a calculation method of lock-up clutch friction work by the mathematical model , and did some further simplified. Meanwhile, the lock-up process was simulated by Matlab/Simulink. By analyzing the simulatin resultthe computed result of machinery bookthe computed result of the improved method, the correctness of the improved method was verified.


Author(s):  
Mauri´cio Baldi ◽  
Pable Siqueira Meirelles

This study proposes a robust and cheap hydropneumatic suspension system for agricultural trailers used to spread crop protection. This kind of vehicle has a high dynamic load factor that increases the axles loads when it is in use and require a height control to assure the same spraying efficiency keeping constant the distance between the spray nozzles and the crop. As the tractor has its own hydraulic system, the hydropneumatic suspension conception take in account that height control will be done by the hydraulic fluid, being the mass of gas kept constant. A mathematical model of the hydropneumatic spring stiffness behavior was developed, as well as a methodology to define the suspension parameters. Experimental validation of the mathematical model was carried out through the use of a real agricultural trailer, equipped with a hydropneumatic suspension projected using the procedure presented, and tested in a hydropuls® road simulator.


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