scholarly journals Vibrational Analysis of Quarter Car Vehicle Dynamic System Subjected to Harmonic Excitation by Road Surface

2012 ◽  
pp. 46-49
Author(s):  
S. H. Sawant ◽  
Mrunalinee V. Belwalkar ◽  
Manorama A. Kamble ◽  
Pushpa B. Khot ◽  
Dipali D. Patil
Keyword(s):  
Dynamic Performance ◽  
Vibrational Analysis ◽  
Design Procedure ◽  
Harmonic Excitation ◽  
Performance Study ◽  
Front Suspension ◽  
Road Profile ◽  
Quarter Car ◽  
Set Up ◽  
Input Motion

A front suspension of Hyundai Elantra 1992 model is assigned as quarter car model and is considered for the performance study. Modeling the dynamic performance of an automobile car system represents a complex task and forms an important step in its design procedure. In this paper the stationary response of quarter car vehicle model moving with a constant velocity over a rough road is considered for the performance study. For this a simplified model and experimental set up is developed. The deterministic impulses due to road profile are given by an eccentric cam which gives input motion to front suspension acting as a follower of the cam. The displacements obtained by FFT analyzer at upper mount of shock absorber were compared with the analytical and MATLAB results.

scholarly journals VIBRATIONAL ANALYSIS OF QUARTER CAR VEHICLE DYNAMIC SYSTEM SUBJECTED TO HARMONIC EXCITATION BY ROAD SURFACE

2012 ◽  
pp. 229-231
Author(s):  
S. H. SAWANT ◽  
MRUNALINEE V. BELWALKAR ◽  
MANORAMA A. KAMBLE ◽  
PUSHPA B. KHOT ◽  
DIPALI D. PATIL
Keyword(s):  
Dynamic Performance ◽  
Vibrational Analysis ◽  
Design Procedure ◽  
Harmonic Excitation ◽  
Performance Study ◽  
Front Suspension ◽  
Road Profile ◽  
Quarter Car ◽  
Set Up ◽  
Input Motion

A front suspension of Hyundai Elantra 1992 model is assigned as quarter car model and is considered for the performance study. Modeling the dynamic performance of an automobile car system represents a complex task and forms an important step in its design procedure. In this paper the stationary response of quarter car vehicle model moving with a constant velocity over a rough road is considered for the performance study. For this a simplified model and experimental set up is developed. The deterministic impulses due to road profile are given by an eccentric cam which gives input motion to front suspension acting as a follower of the cam. The displacements obtained by FFT analyzer at upper mount of shock absorber were compared with the analytical and MATLAB results.

scholarly journals Investigation into the Damping and Stiffness Characteristics of an Elevator Car System

2010 ◽  
Vol 24-25 ◽  
pp. 77-82 ◽  
Author(s):  
I. Herrera ◽  
H. Su ◽  
Stefan Kaczmarczyk
Keyword(s):  
Dynamic Performance ◽  
Design Procedure ◽  
Harmonic Excitation ◽  
Experimental Procedure ◽  
System A ◽  
Damping Characteristics ◽  
Single Person ◽  
Stiffness Characteristics ◽  
Stiffness And Damping ◽  
Experimental Rig

Modelling the dynamic performance of an elevator car system represents a complex task and forms an important step in the elevator system design procedure. The need to consider the behaviour of passengers travelling in the car complicates the procedure further. This paper presents an original approach to identify the stiffness and damping characteristics of an elevator car system. A simplified model is developed and the experimental rig with a rectangular elevator platform fixed on the top of four silent blocks attached to a shaker is setup. The transmissibility measurements are carried out with a harmonic excitation applied first to a platform with no passenger load and then to the platform with one passenger within the frequency range of 1 – 20 Hz. A single person standing on the platform is employed in order to assess the passenger’s contribution to the dynamic behaviour of the elevator car system. The curve fitting technique implemented in MATLAB is used to determine the damping and stiffness coefficients both for the empty car system and the car-passenger system. Investigation on the tolerances for both parameters is carried out. An approach to simplify the experimental procedure and to reduce the number of individual tests is proposed.

Wave propagation improvement in two-dimensional bond-based peridynamics model

2021 ◽  
pp. 095440622098555
Author(s):  
Reza Alebrahim ◽  
Pawel Packo ◽  
Mirco Zaccariotto ◽  
Ugo Galvanetto
Keyword(s):  
Wave Propagation ◽  
Dynamic Performance ◽  
Numerical Dispersion ◽  
Motion Modeling ◽  
Minimization Method ◽  
Irregular Wave ◽  
Point Collocation ◽  
Potential Applications ◽  
Non Local ◽  
Set Up

In this study, methods to mitigate anomalous wave propagation in 2-D Bond-Based Peridynamics (PD) are presented. Similarly to what happens in classical non-local models, an irregular wave transmission phenomenon occurs at high frequencies. This feature of the dynamic performance of PD, limits its potential applications. A minimization method based on the weighted residual point collocation is introduced to substantially extend the frequency range of wave motion modeling. The optimization problem, developed through inverse analysis, is set up by comparing exact and numerical dispersion curves and minimizing the error in the frequency-wavenumber domain. A significant improvement in the wave propagation simulation using Bond-Based PD is observed.

Modelling of the whole process of a university campus CHP power plant and dynamic performance study

2016 ◽  
Vol 13 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Yue Wang ◽  
Akmaral Bermukhambetova ◽  
Ji-Hong Wang ◽  
Mark Donner ◽  
Jun-Fu Lv ◽  
...  
Keyword(s):  
Power Plant ◽  
Dynamic Performance ◽  
University Campus ◽  
Performance Study ◽  
Whole Process

Electromagnetic Shock Absorbers for Automotive Suspensions: Electromechanical Design

2006 ◽  
Author(s):  
Nicola Amati ◽  
Aldo Canova ◽  
Fabio Cavalli ◽  
Stefano Carabelli ◽  
Andrea Festini ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Dynamic Performance ◽  
Integrated Design ◽  
Design Procedure ◽  
Resistive Load ◽  
Added Resistance ◽  
Damping Force ◽  
Quarter Car Model ◽  
Car Model ◽  
Shock Absorbers

This article illustrates the modeling and design of electromechanical shock absorbers for automotive applications. Relative to the commonly used hydraulic shock absorbers, electromechanical ones are based on the use of linear or rotative electric motors. If electric motor is of the DC-brushless type, the shock absorber can be devised by shunting its electric terminals with a resistive load. The damping force can be modified by acting on the added resistance. An integrated design procedure of the electrical and mechanical parameters is presented in the article. The dynamic performance that can be obtained by a vehicle with electromechanical dampers is verified on a quarter car model.

Trajectory Synthesis and Redundancy Resolution for High Speed Point to Point Motions of Redundant Robot Manipulators

1997 ◽  
Author(s):  
W. Kim ◽  
J. Rastegar
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Dynamic Performance ◽  
High Harmonic ◽  
Harmonic Excitation ◽  
Redundancy Resolution ◽  
Tracking Accuracy ◽  
Point To Point

Abstract Trajectory synthesis for robot manipulators with redundant kinematic degrees-of-freedom has been studied by numerous investigators. Redundant manipulators are of interest since the redundant degrees-of-freedom can be used to improve the local and global kinematic and dynamic performance of a system. As a robot manipulator is forced to track a given trajectory, the required actuating torques (forces) may excite the natural modes of vibration of the system. Noting that manipulators with revolute joints have nonlinear dynamics, high harmonic excitation torques are generally generated even though such harmonics have been eliminated from the synthesized trajectories and filtered from the drive inputs. In this paper, a redundancy resolution method is developed based on the Trajectory Pattern Method (TPM) to synthesize trajectories such that the actuating torques required to realize them do not contain higher harmonic components with significant amplitudes. With such trajectories, a robot manipulator can operate at higher speeds and achieve higher tracking accuracy with suppressed residual vibration. As an example, optimal trajectories are synthesized for point to point motions of a plane 3R manipulator.

Performance Study of a Hybrid Heat Pump Dryer based on Numerical Analysis and Experimental Set-up

2020 ◽  
Author(s):  
Mohamed Murshid Shamsuddeen ◽  
Dong-An Cha ◽  
Seon-Chang Kim ◽  
Toshiaki Kanemoto ◽  
Jin-Hyuk Kim
Keyword(s):  
Numerical Analysis ◽  
Heat Pump ◽  
Performance Study ◽  
Hybrid Heat Pump ◽  
Set Up

First-Crossing Problem of Weakly Coupled Strongly Nonlinear Oscillators Subject to a Weak Harmonic Excitation and Gaussian White Noises

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Y. J. Wu ◽  
H. Y. Wang
Keyword(s):  
Harmonic Function ◽  
Degrees Of Freedom ◽  
High Efficiency ◽  
Digital Simulation ◽  
Stochastic Averaging ◽  
Harmonic Excitation ◽  
Van Der Pol Oscillator ◽  
Strongly Nonlinear ◽  
Set Up ◽  
White Noises

We study first-crossing problem of two-degrees-of-freedom (2DOF) strongly nonlinear mechanical oscillators analytically. The excitation is the combination of a deterministic harmonic function and Gaussian white noises (GWNs). The generalized harmonic function is used to approximate the solutions of the original equations. Four cases are studied in terms of the types of resonance (internal or external or both). For each case, the method of stochastic averaging is used and the stochastically averaged Itô equations are obtained. A backward Kolmogorov (BK) equation is set up to yield the failure probability and a Pontryagin equation is set up to yield average first-crossing time (AFCT). A 2DOF Duffing-van der Pol oscillator is chosen as an illustrative example to demonstrate the effectiveness of the analytical method. Numerically analytical solutions are obtained and validated by digital simulation. It is shown that the proposed method has high efficiency while still maintaining satisfactory accuracy.

Dynamic Performance of Conventional and Electrically Activated Engine Thermostats

2001 ◽  
Author(s):  
L. Alan Gunter ◽  
M. Razi Nalim
Keyword(s):  
Heat Transfer ◽  
Dynamic Performance ◽  
Control Device ◽  
The Road ◽  
Engine Control System ◽  
Passive Devices ◽  
Heating Device ◽  
Set Up ◽  
Spool Valve ◽  
Engine Coolant

Abstract This study concerns the dynamic performance of passive and active wax-actuator driven thermostats. The study is extended to wax actuator driven thermostats that have been fitted with a heating device, such that the thermostat can be actuated electrically. The thermostat valve type chosen for this study is a balanced, sleeve-type thermostat typically used in large over-the-road and industrial diesel engines. The valve operates like a spool valve to direct the flow of the engine coolant to the bypass, the heat exchanger, or partially to each. Since conventional thermostats are passive devices they lag in response to dynamic engine conditions, and under certain circumstances overheating can occur as a result of the device’s inability to respond quickly. Also, conventional thermostats are designed to protect an engine against overheating year round. Therefore, a thermostat designed to protect against overheating in the summer will often result in an overcooling condition in the winter. One possible solution to the problem is to control the thermostat electrically through the electronic engine control system, or other system, making the thermostat an active control device instead of a passive one. In this study, a mathematical model is developed to determine wax temperature, and thereby predict the thermostat operation and response. The wax temperature depends on the heat transfer from the engine coolant through the brass cup that encapsulates the wax, as well as heat transfer from the heater. The simulations are compared with measurements of temperature, thermostat position and flow at several locations around the thermostat in an experimental set-up. The outcome is used to analyze the accuracy of the methods used in the thermodynamic calculations.

Design and Performance Study of a Novel Refrigeration System

2011 ◽  
Vol 354-355 ◽  
pp. 819-827
Author(s):  
Yan Ling Liu ◽  
Ling Qun Wang ◽  
Zai Zhong Xia
Keyword(s):  
Cooling Capacity ◽  
The Novel ◽  
Conventional System ◽  
Performance Study ◽  
Continuous Adsorption ◽  
Two Systems ◽  
Refrigerant Circuit ◽  
And Performance ◽  
Set Up ◽  
Similarity And Difference

In order to solve the problems of pressure drop and leakage in the refrigerant circuit, a novel continuous adsorption system suited to use low heat source (75-85 oC) was designed and set up. To analyze and compare with the conventional system to reveal the similarity and difference, this paper sets up the mathematical models for these two systems. The adsorbers, condensers and evaporators in these two systems are exactly the same and the two systems are compared by working at the identical conditions, which is not feasible in real experimental lab. All the parameters and models used in this calculation are based on experimental results. Analysis demonstrates that the two kinds of system have very close performances, that is, the novel system has a relatively higher cooling capacity while the conventional system has a relatively higher COP.

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