A Mechanical Model for Dynamic Behavior of Large Amplitude Liquid Sloshing in Partially Filled Tank Vehicles

2003 ◽  
Author(s):  
Liang Xu ◽  
Liming Dai
Keyword(s):  
Mechanical System ◽  
Dynamic Behavior ◽  
Large Amplitude ◽  
Mechanical Model ◽  
Structure Design ◽  
Liquid Sloshing ◽  
Liquid Motion ◽  
Mass Model ◽  
Longitudinal Dynamic ◽  
Tank Vehicles

A mechanical model of liquid sloshing is developed to investigate the longitudinal dynamic characteristics of partially filled liquid cargo tank vehicles during typical straight-line driving. The dynamic liquid motion is modeled by utilizing a mechanical system that describes the behavior of the liquid motion as a linear spring-mass model augmented with an impact subsystem for longitudinal oscillations. Computer simulation of tank vehicles under rough road conditions is performed by incorporating the forces and moments caused by liquid motion into the pitch plane vehicle model. The fifth wheel loads and the normal axle loads, which are key factors to vehicle structure design, fatigue analysis and vehicle performance characteristics, are computed using the mechanical system approach in order to investigate the influence of liquid motion. This study presents a new approach to investigate the longitudinal dynamic behavior of partially filled tank vehicles under large amplitude liquid sloshing.

A new non-linear approach to analysing the dynamic behaviour of tank vehicles subjected to liquid sloshing

2005 ◽  
Vol 219 (1) ◽  
pp. 75-86 ◽  
Author(s):  
L Dai ◽  
L Xu ◽  
B Setiawan
Keyword(s):  
Dynamic Behaviour ◽  
Linear Models ◽  
Fluid Motion ◽  
Liquid Sloshing ◽  
New Approach ◽  
Linear Dynamic ◽  
Longitudinal Dynamic ◽  
Linear Approach ◽  
Non Linear ◽  
Tank Vehicles

This research presents a new approach to investigating the non-linear dynamic behaviour of partially filled tank vehicles under large-amplitude liquid sloshing. A non-linear impact model for liquid sloshing in partially filled liquid tank vehicles is established for investigating the longitudinal dynamic characteristics of tank vehicles under typical driving conditions. The dynamic fluid motion within the tank is modelled by utilizing an analogy system together with an impact subsystem for longitudinal oscillations. The forces on the fifth wheel and the axles of the vehicle are determined in considering the effects of the liquid sloshing in the tank. The non-linear dynamic behaviours of the tank vehicle subjected to liquid sloshing and the excitations generated by rough roads are analysed and compared with those of linear models. Numerical simulation of the tank vehicle under typical rough road conditions is performed.

Parameter Computation of Equivalent Mechanical Models of Liquid Sloshing in Spacecraft Container

2013 ◽  
Vol 397-400 ◽  
pp. 209-212 ◽  
Author(s):  
Li Xin Zhang ◽  
Zheng Feng Bai ◽  
Yang Zhao ◽  
Xi Bin Cao
Keyword(s):  
Mechanical Model ◽  
Liquid Sloshing ◽  
Equivalent Model ◽  
Parameter Determination ◽  
Mass Model ◽  
Numerical Example ◽  
Equivalent Mechanical Model ◽  
Determination Process ◽  
Pendulum Model ◽  
Mechanical Models

Liquid sloshing is the source of disturbance. General the equivalent mechanical models are used to simulate the liquid sloshing in container. In this paper, the equivalent pendulum model for liquid sloshing is established. Further, the parameter relationship between the equivalent spring-mass model and equivalent pendulum model is presented. Then, parameter determination process of the equivalent mechanical model is proposed. Finally, a numerical example is implemented to calculate the parameters of equivalent model for liquid sloshing in a container.

scholarly journals Equivalent Mechanical Model for Lateral Liquid Sloshing in Partially Filled Tank Vehicles

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Zheng Xue-lian ◽  
Li Xian-sheng ◽  
Ren Yuan-yuan
Keyword(s):  
Cross Sections ◽  
Mechanical Model ◽  
Dynamic Effect ◽  
Liquid Sloshing ◽  
Lateral Acceleration ◽  
New Approach ◽  
Roll Control ◽  
Equivalent Mechanical Model ◽  
Parameter Values ◽  
Tank Vehicles

This paper reports a new approach to investigating sloshing forces and moments caused by liquid sloshing within partially filled tank vehicles subjected to lateral excitations. An equivalent mechanical model is used in the paper to approximately simulate liquid sloshing. The mechanical model is derived by calculating the trajectory of the center of gravity of the liquid bulk in tanks as the vehicle’s lateral acceleration changes from 0 to 1 g. Parametric expressions for the model are obtained by matching the dynamic effect of the mechanical model to that of liquid sloshing. And parameter values of a liquid sloshing dynamic effect, such as sloshing frequency and forces, are acquired using FLUENT to simulate liquid sloshing in tanks with different cross-sections and liquid fill percentages. The equivalent mechanical model for liquid sloshing in tank vehicles is of a great significance for simplifying the research on roll stability of tank vehicles and for developing active/passive roll control systems for these vehicles.

Study of the dynamics of ТПА 350 automatic mill working stand elements

2020 ◽  
Vol 76 (8) ◽  
pp. 830-840
Author(s):  
S. R. Rakhmanov ◽  
V. V. Povorotnii
Keyword(s):  
Mechanical System ◽  
Dynamic Model ◽  
Maximum Amplitude ◽  
Calculation Scheme ◽  
Dynamic Loads ◽  
Forced Oscillations ◽  
Mass Model ◽  
Automatic Mill ◽  
Hollow Billet ◽  
Oscillation Movement

To form a necessary geometry of a hollow billet to be rolled at a pipe rolling line, stable dynamics of the base equipment of the automatic mill working stand has a practical meaning. Among the forces, acting on its parts and elements, significant by value short-time dynamic loads are the least studied phenomena. These dynamic loads arise during transient interaction of the hollow billet, rollers, mandrel and other mill parts at the forced grip of the hollow billet. Basing of the calculation scheme and dynamic model of the mechanical system of the ТПА 350 automatic mill working stand was accomplished. A mathematical model of dynamics of the system “hollow billet (pipe) – working stand” within accepted calculation scheme and dynamic model of the mechanical system elaborated. Influence of technological load of the rolled hollow billet variation in time was accounted, as well as variation of the mechanical system mass, and rigidity of the ТПА 350 automatic mill working stand. Differential equations of oscillation movement for four-mass model of forked sub-systems of the automatic mill working stand were made up, results of their digital calculation quoted. Dynamic displacement of the stand elements in the inter-roller gap obtained, which enabled to estimate the results of amplitude and frequency characteristics of the branches of the mill rollers setting. It was defined by calculation, that the maximum amplitude of the forced oscillations of elements of the ТПА 350 automatic mill working stand within the inter-roller gap does not exceed 2 mm. It is much higher than the accepted value of adjusting parameters of the deformation center of the ТПА 350 automatic mill. A scheme of comprehensive modernization of the rollers setting in the ТПА 350 automatic mill working stand was proposed. It was shown, that increase of rigidity of rollers setting in the ТПА 350 automatic mill working stand enables to stabilize the amplitude of forced oscillations of the working stand elements within the inter-rollers gap and considerably decrease the induced nonuniform hollow billet wall thickness and increase quality of the rolled pipes at ТПА 350.

Longitudinal Dynamic Behavior of Bridges due to Train Braking

2000 ◽  
Vol 16 (18) ◽  
pp. 621-628
Author(s):  
JongWon KWARK ◽  
SungIll KIM ◽  
SungPil CHANG ◽  
ByungSuk KIM
Keyword(s):  
Dynamic Behavior ◽  
Longitudinal Dynamic

Structure Damage Detection via the Behavior of Substructure

1991 ◽  
Author(s):  
J. H. Wang ◽  
C. S. Liou
Keyword(s):  
Damage Detection ◽  
Mechanical System ◽  
Dynamic Behavior ◽  
Structural Damage ◽  
Structure Damage

Abstract A mechanical system generally consists of many substructures. However, it is impossible to observe the dynamic behavior of any substructure directly when the whole structure is in operation. A method was proposed in this work to determine the FRFs of a substructure by using the measured FRFs of the whole structure and the priorly known FRFs of another substructure With this method, one can detect the structural damage more easily by observing the change of the FRFs of the damaged substructure.

High-frequency vibration energy harvesting from repeated impulsive forcing utilizing intentional dynamic instability caused by strong nonlinearity

2016 ◽  
Vol 28 (4) ◽  
pp. 468-487 ◽  
Author(s):  
Kevin Remick ◽  
D Dane Quinn ◽  
D Michael McFarland ◽  
Lawrence Bergman ◽  
Alexander Vakakis
Keyword(s):  
Energy Harvesting ◽  
Mechanical System ◽  
High Frequency ◽  
Large Amplitude ◽  
Electromechanical Coupling ◽  
Dynamic Instability ◽  
Vibration Energy ◽  
Primary System ◽  
Vibration Energy Harvesting ◽  
Strongly Nonlinear

The work in this study explores the excitation of high-frequency dynamic instabilities to enhance the performance of a strongly nonlinear vibration-based energy harvesting system subject to repeated impulsive excitations. These high-fraequency instabilities arise from transient resonance captures (TRCs) in the damped dynamics of the system, leading to large-amplitude oscillations in the mechanical system. Under proper forcing conditions, these high-frequency instabilities can be sustained. The primary system is composed of a grounded, weakly damped linear oscillator, which is directly subjected to impulsive forcing. A light-weight, damped nonlinear oscillator (nonlinear energy sink, NES) is coupled to the primary system using electromechanical coupling elements and strongly nonlinear stiffness elements. The essential (nonlinearizable) stiffness nonlinearity arises from geometric and kinematic effects resulting from the traverse deflection of a piano wire coupling the two oscillators. The electromechanical coupling is composed of a neodymium magnet and inductance coil, which harvests the energy in the mechanical system and transfers it to the electrical system which, in this present case, is composed of a simple resistive element. The energy dissipated in the circuit is inferred as a measure of energy harvesting capability. The large-amplitude TRCs result in strong, nearly irreversible energy transfer from the primary system to the NES, where the harvesting elements work to convert the mechanical energy to electrical energy. The primary goal of this work is to numerically and experimentally demonstrate the efficacy of inducing sustained high-frequency dynamic instability in a system of mechanical oscillators to achieve enhanced vibration energy harvesting performance. This work is a continuation of a companion paper (Remick K, Quinn D, McFarland D, et al. (2015) Journal of Sound and Vibration Final Publication) where vibration energy harvesting of the same system subject to single impulsive excitation is studied.

BUILDING MODELS FOR QUALITATIVE PREDICTION OF SYSTEM DYNAMIC BEHAVIOR

1993 ◽  
Vol 07 (03) ◽  
pp. 493-512
Author(s):  
SUKHAN LEE ◽  
JUDY CHEN
Keyword(s):  
Problem Solving ◽  
Mechanical System ◽  
Dynamic Behavior ◽  
A Algorithm ◽  
Qualitative Simulation ◽  
Critical States ◽  
Physical Description ◽  
Building Models ◽  
Minimum Uncertainty ◽  
Necessary And Sufficient

This paper presents a method of automatically constructing a model or a set of constraints from domain principles for solving the dynamic behavior of a mechanical system through qualitative simulation. It emphasizes the following issues: the extraction of a set of necessary and sufficient constraints which provides the minimum uncertainty associated with qualitative simulation, from the fundamental principles and laws of physics based solely on the physical description of a given mechanical system; and the modification of constraints through time by detecting and identifying “system discontinuities” due to collisions, separations, and other critical states associated with each of the object primitives. The first is accomplished by describing a mechanical system by a collection of object and inter-connection primitives, which allows direct instantiating of all the relevant physics laws from the knowledge base. Then, the final set of constraints having the minimum complexity and uncertainty is extracted from the relevant physics laws, based on an A* algorithm with heuristics providing the problem solving expertise. The second is accomplished by monitoring whether the states of any individual sub-systems evolve to system discontinuities represented by intra/inter subsystem critical states.

Dynamic Behavior of Bi-Axial Self-Synchronous Shaker with Translation Elliptic Trace

2011 ◽  
Vol 211-212 ◽  
pp. 406-410
Author(s):  
Wei Bing Zhu ◽  
Cheng Zhong Deng ◽  
He Shun Wang
Keyword(s):  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Dynamic Strength ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Structure Design ◽  
Experiment Research ◽  
Design Improvement ◽  
Oscillation Modes ◽  
Stress And Deformation

According to the self-synchronous theory with two vibrating electric motors, a translation elliptic shaker is designed, and its finite element model for the sieving box is established. The dynamic behavior analysis of the sieving box is reached with CATIA software. The natural frequencies and modal oscillation modes of the sieving box are calculated, and the stress and deformation distribution in every part of the sieving box under rated load are obtained. All shows that, its structure design is reasonable. Under the designed working conditions, the maximum principal stress of the side boards is 39.7 MPa, and its dynamic strength is satisfied. The calculating results will be of significance to the design improvement, and give a basis for the experiment research of dynamic strength.

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