Dynamic Behavior of Finite Coupled Mindlin Plates With a Blocking Mass

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
XianZhong Wang
Keyword(s):  
Dynamic Behavior ◽  
Power Flow ◽  
Equations Of Motion ◽  
Flow Analysis ◽  
Input Power ◽  
Dynamic Responses ◽  
Structural Damping ◽  
Arbitrary Angle ◽  
Plate Equations ◽  
Coupled Plates

A power flow analysis of finite coupled Mindlin plates with a blocking mass at the junction of the coupled plates is investigated using the method of reverberation-ray matrix (MRRM). An exact solution is derived by the plate equations of motion to satisfy the boundary condition. The wave amplitude coefficients are obtained from the continuity conditions at driving force locations, and the line junction of two plates connected at an arbitrary angle. The blocking mass located at the junction of the two plates is modeled as a Timoshenko beam. The dynamic responses of the finite coupled Mindlin plates are verified by comparing with finite element method (FEM) results. The effects of the connected angles, blocking mass, and structural damping on the input power and transmitted power are calculated and analyzed. Numerical simulations of the finite coupled Mindlin plates with a blocking mass show that the present method can predict the dynamic behavior.

Dynamics of MEMS-Based Angular Rate Sensors Excited via External Electrostatic Forces

2020 ◽  
Author(s):  
Ibrahim F. Gebrel ◽  
Ligang Wang ◽  
Samuel F. Asokanthan
Keyword(s):  
Dynamic Behavior ◽  
Electrostatic Force ◽  
Angular Rate ◽  
Equations Of Motion ◽  
Ring Structure ◽  
Dynamic Responses ◽  
Actuator Dynamics ◽  
Vibratory Gyroscopes ◽  
Thin Ring ◽  
The Mathematical Model

Abstract This paper investigates the dynamic behavior of rotating MEMS-based vibratory gyroscopes which employs a thin ring as the vibrating flexible element. The mathematical model for the MEMS ring structure as well as a model for the nonlinear electrostatic excitation forces are formulated. Galerkin’s procedure is employed to reduce the equations of motion to a set of ordinary differential equations. Understanding the effects of nonlinear actuator dynamics is considered important for characterizing the dynamic behavior of such devices. A suitable theoretical model to generate nonlinear electrostatic force that acts on the MEMS ring structure is formulated. Dynamic responses in the driving and the sensing directions are examined via time responses, phase diagram, and Poincare’ map plots when the input angular motion and the nonlinear electrostatic force are considered simultaneously. The analysis is envisaged to aid fabrication of this class of devices as well as for providing design improvements in MEMS Ring-based Gyroscopes.

Dynamic Behavior of the Band/Wheel Mechanical System of Industrial Band Saws

1995 ◽  
Author(s):  
Y. Y. Chung ◽  
C. K. Sung
Keyword(s):  
Mechanical System ◽  
Dynamic Behavior ◽  
Tilt Angle ◽  
Metal Cutting ◽  
Equations Of Motion ◽  
Continuity Condition ◽  
Dynamic Responses ◽  
Moving Beam ◽  
Band Saw ◽  
The Mathematical Model

Abstract This paper presents an analytical and experimental investigation on the dynamic behavior of the band/wheel mechanical system of an industrial metal-cutting band saws. In practice, as a result of the existence of the wheel tilt angle, a pair of roller bearings in which one of them is movable must be employed to twist the saw band perpendicular to the workpiece. Therefore, the saw band is modelled as a finite moving beam span that composes of three consecutive segments, in which the middle segment, that is, the cutting span, and the neighboring two segments may be assumed to be a straight and a twisted beams, respectively. The deformation of the band must satisfy the continuity condition at the connections between segments. The equations of motion governing the dynamic behavior of the beam span in axial, torsional and transverse directions are derived using mixed variational principle. The axial motion of the beam span couples linearly with its torsional motion. The dynamic responses and the natural frequencies of the beam are computed when parameters vary, such as the transport velocity of the saw band, band tension, wheel tilt angle, and the length of the cutting span. Finally, an experimental study is performed on an industrial band saw for the verification of the mathematical model and the predictive capability proposed in this investigation. Favorable comparisons between the analytical and experimental results are obtained.

Nonlinear Input Power Flow Analysis of a Plate with a Breathing Crack

2014 ◽  
Vol 638-640 ◽  
pp. 163-167
Author(s):  
Zhong Hao Pang ◽  
Xiang Zhu ◽  
Tian Yun Li ◽  
Ling Zhang
Keyword(s):  
Nonlinear Dynamic ◽  
Power Flow ◽  
Damage Identification ◽  
Flow Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Nonlinear Behavior ◽  
Input Power ◽  
Breathing Crack ◽  
Engineering Structures ◽  
Power Characteristics

Plates are commonly used in engineering structures. However crack is the most common form of damages in the plate structures. The crack in the plate will open and close during vibrational cycle, making the cracked structure with nonlinear dynamic characteristics. Based on vibrational power flow theory, the nonlinear dynamic analysis of a plate structure is carried out. The contact elements are used to simulate the nonlinear behavior of the breathing crack. Aiming to study the input power characteristics and the super harmonic resonance of a breathing cracked plate which is under the resonant excitation. By the finite element calculation, the structural input power curve is analyzed, which provides a theoretical basis for the damage identification of cracked structures.

Vibrational Power Flow Analysis of Stiffened Plate and Shell Structures

2011 ◽  
Vol 66-68 ◽  
pp. 1897-1901 ◽  
Author(s):  
Xiang Zhu ◽  
Gong Yu Xiao ◽  
Tian Yun Li ◽  
Xiao Fang Hu
Keyword(s):  
Cylindrical Shell ◽  
Power Flow ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Input Power ◽  
Shell Structures ◽  
Stiffened Plate ◽  
Simply Supported ◽  
Plate And Shell ◽  
Flow Vectors

In this paper, the vibration and power flow characteristics of stiffened plate and cylindrical shell structures are investigated by using finite element method. The power flow formulas of basic shell structural elements are given at first. Then a simply supported plate and stiffened plate’s input power flow characteristics and power flow vectors are investigated. The effects of stiffeners in plates are discussed. For a simply supported cylindrical shell, the influence of the structural damping, viscous damper and stiffeners on the cylindrical shell’s input power flow characteristics and propagated power flow characteristics are discussed in detail. The power flow vectors are visualized to reveal the distribution of energy in the shell structures. Some useful conclusions are drown and helpful for the vibration control of plate and shell structures.

Dynamic Behavior of the Band/Wheel Mechanical System of Industrial Band Saws

1998 ◽  
Vol 120 (4) ◽  
pp. 842-847 ◽  
Author(s):  
Y. Y. Chung ◽  
C. K. Sung
Keyword(s):  
Mechanical System ◽  
Dynamic Behavior ◽  
Tilt Angle ◽  
Metal Cutting ◽  
Equations Of Motion ◽  
Continuity Condition ◽  
Dynamic Responses ◽  
Initial Tension ◽  
Saw Blade ◽  
Band Saw

This paper presents an analytical and experimental investigation on the dynamic behavior of the band/wheel mechanical system of an industrial metal-cutting band saws. In practice, this machine is equipped with two pairs of roller bearings to twist the saw blade perpendicularly to the surface of the workpiece. This results in the existence of the wheel tilt angle. The saw band is modeled as a finite moving beam span that composes three consecutive segments: the middle straight segment, that is, the cutting span, and the neighboring two segments that are considered as twisted beams. The deformation of the band must satisfy the continuity condition at the connections between segments. The equations of motion governing the dynamic behavior of the saw band in axial, torsional and transverse directions are derived using mixed variational principle. The axial motion of the span couples linearly with its torsional motion. The dynamic responses and the natural frequencies of the beam are computed when parameters vary, such as the transport velocity of the saw band, initial tension, wheel tilt angle, and the length of the cutting span. Finally, an experimental study is performed on an industrial band saw for the verification of the mathematical model and the predictive capability proposed in this investigation. Favorable comparisons between the analytical and experimental results are obtained.

scholarly journals A New Method to Perform Direct Efficiency Measurement and Power Flow Analysis in Vibration Energy Harvesters

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2388
Author(s):  
Jan Kunz ◽  
Jiri Fialka ◽  
Stanislav Pikula ◽  
Petr Benes ◽  
Jakub Krejci ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Polyvinylidene Fluoride ◽  
Power Flow ◽  
Flow Analysis ◽  
Lead Zirconate ◽  
Input Power ◽  
Mechanical Power ◽  
Vibration Source ◽  
Energy Harvesters ◽  
The Difference

Measuring the efficiency of piezo energy harvesters (PEHs) according to the definition constitutes a challenging task. The power consumption is often established in a simplified manner, by ignoring the mechanical losses and focusing exclusively on the mechanical power of the PEH. Generally, the input power is calculated from the PEH’s parameters. To improve the procedure, we have designed a method exploiting a measurement system that can directly establish the definition-based efficiency for different vibration amplitudes, frequencies, and resistance loads. Importantly, the parameters of the PEH need not be known. The input power is determined from the vibration source; therefore, the method is suitable for comparing different types of PEHs. The novel system exhibits a combined absolute uncertainty of less than 0.5% and allows quantifying the losses. The approach was tested with two commercially available PEHs, namely, a lead zirconate titanate (PZT) MIDE PPA-1011 and a polyvinylidene fluoride (PVDF) TE LDTM-028K. To facilitate comparison with the proposed efficiency, we calculated and measured the quantity also by using one of the standard options (simplified efficiency). The standard concept yields higher values, especially in PVDFs. The difference arises from the device’s low stiffness, which produces high displacement that is proportional to the losses. Simultaneously, the insufficient stiffness markedly reduces the PEH’s mechanical power. This effect cannot be detected via the standard techniques. We identified the main sources of loss in the damping of the movement by the surrounding air and thermal losses. The latter source is caused by internal and interlayer friction.

Vibration Analysis and Energy Transmission of Finite Coupled Mindlin Plates

2017 ◽  
Vol 17 (07) ◽  
pp. 1771007 ◽  
Author(s):  
Xian-Zhong Wang
Keyword(s):  
Power Flow ◽  
Plane Waves ◽  
Flow Analysis ◽  
Mindlin Plate ◽  
Rectangular Plates ◽  
The Finite Element Method ◽  
Energy Transmission ◽  
Local Coordinates ◽  
Out Of Plane ◽  
Coupled Plates

Power flow analysis of finite coupled Mindlin plates and energy transmission through the structure are investigated by employing the method of reverberation-ray matrix (MRRM). The rectangular Mindlin plates are connected at an arbitrary angle. Both in-plane and out-of-plane waves propagation solutions are considered by establishing the dual local coordinates in each plate. The boundary conditions at the plate edges, continuous conditions at the driving force locations, and coupling conditions at the line junction between several rectangular plates are established and solved simultaneously. Then the flexural and in-plane vibrations of the finite coupled Mindlin plate are obtained by using the MRRM, which are verified by comparing the results obtained with those by the finite element method (FEM). The vibration behaviors of coupled plates such as L-shaped structure, T-shaped structure and box-shaped structure are calculated and verified.

A Systematic Approach to Power-Flow and Static-Force Analysis in Epicyclic Spur-Gear Trains

1993 ◽  
Vol 115 (3) ◽  
pp. 639-644 ◽  
Author(s):  
E. Pennestri` ◽  
F. Freudenstein
Keyword(s):  
Power Flow ◽  
Systematic Approach ◽  
Flow Analysis ◽  
Spur Gear ◽  
Input Power ◽  
Static Force ◽  
Force Analysis ◽  
Systematic Method ◽  
Gear Trains ◽  
Gear Drives

It is well known that the circulating power in gear trains can be many times greater than the input power. Such circumstances require that in the design of split-power gear drives, a preliminary power-flow analysis be carried out. In this investigation a systematic method for the power-flow and static-force analysis of spur-gear drives is presented. The manner in which the procedure is applied has some similarities with an algorithm for kinematic analysis previously suggested by one of the authors. Following a brief review of previous work, the theoretical bases of the new methodology of analysis are discussed and numerical examples developed.

scholarly journals DC RAILWAY POWER FLOW ANALYSIS FOR ADDIS ABABA LIGHT RAIL TRANSIT USING NEWTON RAPHSON METHOD

2021 ◽  
Vol 9 (5) ◽  
pp. 744-759
Author(s):  
Mugisho Mugaruka Josue ◽  
◽  
Regis Nibaruta ◽  
Keyword(s):  
Power Flow ◽  
Addis Ababa ◽  
Flow Analysis ◽  
Input Power ◽  
Light Rail ◽  
Rail Transit ◽  
Dc Power ◽  
Tractive Effort ◽  
Line Section ◽  
Raphson Method

This paper uses Newton–Raphson method for DC power flow analysis of the Addis Ababa light Rail Transit (AALRT). The study focuses onthe line section from Menilik II square station up to Lideta station. First the tractive effort required by the trains for different scenarios such as train movement in a straight line, a curved line, and a line with gradient is computed as the chosen line section contains all these scenarios. Then the total input power will be calculated using computed tractive effort obtained for each scenario and using other input parameters obtained from AALRT, and different papers. The input power for the different loads is computed, and the input power is used to analyse the bus voltage for different loads and train positions. Newton Raphson Method is used to solve the DC Power bus problem assuming that the train requires constant power while moving between two feeding stations. Even if using the rail as the return conductor for DC traction systems has economic advantages, it has some limitations like the rail potential and stray current. A rail potential study is carried out and conclusions are drawn. The result shows that the maximum voltage drop was 0.1 p.u and the train power consumption increases by 136.73 kW as the train takes a gradient of 3.92% and keep increasing again by 29.17kw with a curve resistance (100 meters). The Rail potential moves from 6.0139V to 29.85V proportionally with the variation of the total ground resistance.

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