Effect of Tapered Guide Shape on Spaghetti Problems

2003 ◽  
Author(s):  
Nobuyuki Kobayashi ◽  
Yoshimasa Komaki ◽  
Takamune Irie ◽  
Masahiro Watanabe
Keyword(s):  
Mechanical Model ◽  
Constant Velocity ◽  
Experimental Investigations ◽  
Flexible Beam ◽  
Thin Beam ◽  
Finite Segment ◽  
Oscillation Mechanism ◽  
Elastic Wall ◽  
Simulation And Experiment ◽  
Simulation Results

The dynamic behavior of a flexible beam that is pulled into an opening in an elastic wall with a constant velocity is studied using a mechanical model and experiments. We focus particularly on the effects of the tapered guide that is provided in front of the inlet of the wall gap on the beam behavior. We developed a finite-segment-based model for flexibility of the beam, and the nonlinear spring and damper are introduced for representing the stiffness of the inlet of the elastic wall gap and the tapered guide. Experimental investigations are conducted with FRP thin beam as the Spaghetti, and compared their results with numerical simulation results. As the results of simulation and experiment, the effects of the tapered guide angle guide length and the pulling velocity on oscillation mechanism of the Spaghetti are discussed.

Experimental and Analytical Investigation on Spaghetti Problem

2001 ◽  
Author(s):  
Yoshimasa Komaki ◽  
Nobuyuki Kobayashi ◽  
Masahiro Watanabe
Keyword(s):  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Constant Velocity ◽  
Analytical Investigation ◽  
Experimental Results ◽  
Flexible Beam ◽  
Gap Size ◽  
Lateral Vibration ◽  
Elastic Wall ◽  
Pulling Velocity

Abstract The dynamic behavior of the flexible beam, which is pulled into the slit of the elastic wall with a constant velocity, is discussed with multibody dynamics formulation and experiments. The vibration of the free tip of a flexible beam increases rapidly as pulling into the slit, and this behavior is called “Spaghetti Problem”. The effect of gap size of the slit on the behavior of Spaghetti Problem is especially focused. Dynamic behavior of the beam is simulated numerically and examined the accuracy of the presented formulation by changing the gap size and the pulling velocity of the beam as parameters. It is clarified that the presented modeling method simulates the experimental results quite well, and the gap size and the pulling velocity influence the increase of the lateral vibration near the inlet of the slit.

Numerical Simulation and Experimental Research on Pedestal Looseness of a Rotor System

2007 ◽  
Author(s):  
Hui Ma ◽  
Hong Liang Yao ◽  
Zhao Hui Ren ◽  
Feng Wen ◽  
Bang Chun Wen
Keyword(s):  
Numerical Simulation ◽  
Mechanical Model ◽  
Test Rig ◽  
Rotating Speed ◽  
Runge Kutta Method ◽  
Motion State ◽  
Simulation And Experiment ◽  
State Changes ◽  
Simulation Results ◽  
Set Up

The mechanical model of looseness of fastening bolt on the bearing pedestal is set up based on the project practice. Using the nonlinear oil-film model put forward by Adiletta, the dynamic characteristics were investigated by numerical Runge-Kutta method. At last, the experiment is performed to investigate the pedestal looseness by a test rig and the fault signals are analyzed by the spectrum cascade and reassigned wavelet scalogram. Numerical simulation and experiment all show that system motion state changes frequently with the increase of the rotating speed. And the experimental results coincide with the simulation results.

Simulation and Experimental Study on Improving Electrochemical Machining Stability of High Convex Structure on Casing Surface by Using Backwater Pressure

2021 ◽  
Author(s):  
Zhenghui Ge ◽  
Wangwang Chen ◽  
Yongwei Zhu
Keyword(s):  
Flow Field ◽  
Electrochemical Machining ◽  
Back Pressure ◽  
Convex Structure ◽  
Flow Field Characteristics ◽  
Simulation And Experiment ◽  
Different Shapes ◽  
Simulation Results ◽  
Structure Height ◽  
Engine Components

Abstract Casing parts are regarded as one of the key components in aero-engine components. Most casing parts are attached with different shapes of convex structures, and their heights range from hundreds of microns to tens of millimeters. The use of profiling blocky electrodes for electrochemical machining of casing parts is a widely used method, especially in the processing of high convex structures. However, with the increase of convex structure height, the flow field of machining areas will become more complex, and short circuits may occur at any time. In this study, a method to improve the flow field characteristics of machining area by adjusting the backwater pressure is proposed, the simulation and experiment are carried out respectively. The simulation results showed that the back-pressure mehtod can significantly improve the uniformity of the flow field around the convex structure compared with the extraction outlet mode and the open outlet mode, and then the optimized back-pressure of 0.5 MPa was obtained according to simulation results. The experimental results showed that under condition of the optimized back-pressure parameters, the cathode feed-rate increased from 0.6 mm/min to 0.8 mm/min, and the convex structure with a height of 18 mm was successfully machined. This indicated that the back-pressure method is suitable and effective for the electrochemical machining of high convex structure with blocky electrode.

Hydraulic Actuator Tuning in the Control of a Rotating Flexible Beam Mechanism

1995 ◽  
Author(s):  
Michael J. Panza ◽  
Roger W. Mayne
Keyword(s):  
Hydraulic Resistance ◽  
System Model ◽  
Flexible Beam ◽  
Hydraulic Actuator ◽  
Control Effort ◽  
Actuation System ◽  
Wide Range ◽  
Position Feedback ◽  
Simulation Results ◽  
Beam Mechanism

Abstract The end point position and vibration control of a rotating flexible beam mechanism driven by a hydraulic cylinder actuator is considered. An integrated nonlinear system model comprised of beam dynamics, hydraulic actuator, control valves, and control scheme is presented. Control based on simple position feedback along with a hydraulic actuation system tuned to suppress beam vibration over a wide range of angular motion is investigated. For positioning to small to moderate mechanism angles, a linear system model with the actuator tuned for good open loop performance is developed. Actuator tuning is accomplished by varying the system hydraulic resistance according to a dimensionless parameter defining the interaction between the actuator and flexible beam. Simulation results for a closed loop system indicate that this simple tuned control provides comparable performance and requires less control effort than an untuned system with a more complex state feedback optimal controller. To compensate for geometric nonlinearities that cause instability when positioning to large mechanism angles, an active actuator tuning scheme based on continuous variation of hydraulic resistance is proposed. The active variable resistance controller is combined with simple position feedback and designed to provide a constant dimensionless actuator-flexible beam interaction parameter throughout the motion. Simulation results are presented to show the stabilizing effect of this control strategy.

scholarly journals Design and Manufacture of a Novel Sunlight Guiding Panel

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 562
Author(s):  
Wei-Hsuan Hsu ◽  
Yi-Zhang Xie
Keyword(s):  
Energy Consumption ◽  
Nanoimprint Lithography ◽  
Window Glass ◽  
Elevation Angle ◽  
Experimental Investigations ◽  
Technological Advancement ◽  
Total Energy Consumption ◽  
Application Potential ◽  
Simulation Results ◽  
Design And Manufacture

With technological advancement, energy consumption and lack of energy supply are inevitable. Approximately 20% of total energy consumption is used for artificial light in standard office buildings. To reduce energy consumption for illumination purposes, a sunlight guiding panel was used to increase the amount of sunlight available indoors. However, in most designs of a sunlight guiding panel, the panel has to be placed on the outdoor surface of a window glass. This type of design is inconvenient for assembling and cleaning. To enhance the practicality of a sunlight guiding panel, we attempted to place the sunlight guiding panel on the indoor surface of a window glass. The simulation results revealed that when the sunlight guiding panel was placed on the indoor surface of a window glass, the aspect ratio of the light-guiding structure of the sunlight guiding panel had to be increased for guiding the sunlight from outdoors so as to increase the amount of sunlight indoors. To fabricate the proposed sunlight guiding panel, UV nanoimprint lithography was applied to pattern the light-guiding structure of the sunlight guiding panel. Moreover, a mold with a high-precision light-guiding structure was used in UV nanoimprint lithography. The mold was fabricated using ultraprecision machining technology. Both analytical and experimental investigations were conducted to confirm the proposed design. The average light-guiding efficiency was 89.9% with a solar elevation angle range of 35° to 65°, and the experimental results agreed well with the simulation results. This study elucidates light-guiding efficiency when the sunlight guiding panel is placed on the indoor surface of a window glass, which can increase the usage convenience and application potential of sunlight guiding panels.

scholarly journals Chemo-Mechanical Model for the Expansion of Concrete Due to Alkali Silica Reaction

2020 ◽  
Vol 10 (11) ◽  
pp. 3807 ◽  
Author(s):  
Lianfang Sun ◽  
Xingji Zhu ◽  
Xiaoying Zhuang ◽  
Goangseup Zi
Keyword(s):  
Experimental Data ◽  
Mechanical Model ◽  
Pore Solution ◽  
Damage Model ◽  
Alkali Silica Reaction ◽  
Swelling Capacity ◽  
Simulation Results

A chemo-damage model is proposed to predict the expansion caused by the alkali silica reaction (ASR). The model covers the formation of the pre-expansion gel driven by alkali and the swelling of the gel driven by water. The swelling capacity of the ASR gel is quantified by the sodium to calcium ratio in the pore solution. The bound alkali in the gel recycled by calcium is also considered in this model. Both external alkali supply and internal alkali released from aggregates are included. Several sets of experimental data are compared with the simulation results for the verification of the model.

The Feasibility Analysis of the Double-Curved Positive Displacement Motor (PDM) Into Casing

2010 ◽  
Vol 143-144 ◽  
pp. 1102-1106
Author(s):  
Xiao Hua Zhu ◽  
Yuan Gao ◽  
Shao Hu Liu ◽  
Hua Tong
Keyword(s):  
Stress Distribution ◽  
Yield Strength ◽  
Mechanical Model ◽  
Maximum Stress ◽  
Feasibility Analysis ◽  
Positive Displacement ◽  
Common Structure ◽  
Simulation Results ◽  
The Law ◽  
Self Gravity

To study the feasibility of double-curved PDM into casing, the mechanical model of Φ172 mm double-curved PDM into Φ244 mm straight casing is established. The effect of different structure corners on the feasibility is analyzed for the PDM into casing; and the law of stress distribution is discussed in the paper. The simulation results show that the Φ172 mm double-curved PDM can enter Φ244 mm straight casing favorably by self-gravity when the first structure bend is equal to 1° and the second structure bend is equal to or less than 1.5°. When the second structure corner is equal to or more than 1.75°, PDM needs extra to enter into casing. Within the bounds of common structure corners,when the PDM into casing, the maximum stress value of the double-curved PDM is much lower than yield strength.

The Design of a MEMS Surface Resonant Magnetometer

2009 ◽  
Vol 60-61 ◽  
pp. 265-269
Author(s):  
Mu Zhi Hu ◽  
Zheng You ◽  
Jian Zhong Yang ◽  
Ling Qi Wu
Keyword(s):  
Mechanical Model ◽  
Sensitive Element ◽  
Simple Structure ◽  
Theoretical Calculations ◽  
High Sensitivity ◽  
Harmonic Excitation ◽  
First Order ◽  
Good Accordance ◽  
Simulation Results ◽  
The Magnetic Field

In this paper, a MEMS surface resonant magnetometer based on Lorentz force is presented. This magnetometer has three current carriers to sense the magnetic field and changes into deflection of beams which will be detected by the comb-capacitance. The alternating current carried by oscillate beams has the same frequency as resonant frequency of the magnetometer structure to make the deflection magnified Q (Quality-factor) times, therefore, it becomes more easily to measure. In this paper, the mechanical model of the sensitive element is established. The equations of stiffness of the system, deflection, first-order resonance frequency and sensitivity are setup and simulated in ANSYS, as well as second-order to fourth-order modal, and harmonic excitation response simulation. It can be seen that the simulation results are in good accordance with the theoretical calculations, which proves the feasibility and the rationality of the theoretical model. The dimensions of the structure are designed, as well as the processing sequence Anodic Silicon-Glass Bonding and Silicon DRIE Multi-user Bulk Micromachining Process which will be used to manufacture the magnetometer. The MEMS surface resonant magnetometer has a high sensitivity, simple structure and easy to manufacture. The prototype sensors are being manufactured in NEDI now.

Simulation and Experiment Researches on Acoustic Field of Spherical Shell Focused Ultrasonic Transducer

2013 ◽  
Vol 770 ◽  
pp. 281-284
Author(s):  
Zhen Yin ◽  
Hua Li ◽  
Zi Yang Cao ◽  
Yu Can Fu
Keyword(s):  
Spherical Shell ◽  
Acoustic Field ◽  
Acoustic Pressure ◽  
Ultrasonic Transducer ◽  
Pressure Curve ◽  
Bending Vibration ◽  
Element Simulation ◽  
Ultrasonic Technology ◽  
Simulation And Experiment ◽  
Simulation Results

Aiming at the deficiency of existing focused ultrasonic technology, a new high-power Spherical Shell Focused Ultrasonic Transducer (SSFUT) was designed. The SSFUT is composed of a sandwich piezoelectric ultrasonic transducer and a bending vibration spherical shell. Simulation on acoustic field of SSFUT was carried out. the acoustic field pressure distribution nephogram and the axial acoustic pressure curve of the SSFUT were obtained. The consistency of finite element simulation results and experimental results was verified by testing. The research provides a theoretical basis for implementation and application of the new focused ultrasonic technology.

Dynamical Research on a Micro-Displacement Actuator Based on V-Type Guide-Way

2011 ◽  
Vol 305 ◽  
pp. 330-334
Author(s):  
Ji Jie Ma ◽  
Jian Ming Wen ◽  
Ping Zeng ◽  
Jun Wu Kan ◽  
Zhong Hua Zhang
Keyword(s):  
High Resolution ◽  
Electrical Signal ◽  
Loading Capacity ◽  
Kinetic Simulation ◽  
Working Mechanism ◽  
Dynamic Formulation ◽  
Simulation And Experiment ◽  
New Type ◽  
Simulation Results ◽  
Inertial Actuator

A new type of the micro-displacement device based on V-shaped groove by using piezoelectric stack as the driver was presented. The performance characteristic of the driving device was introduced and its working mechanism was discussed. the dynamic formulation of inertial actuator is established, by using matlab software, the kinetic simulation of the actuator is carried out, the structure of newly inertial actuator is designed and manufactured. The simulation and experiment of the actuator is conducted. The simulation results agree well with the experimental results indicates that the simple associated symmetry electrical signal can provide stable stepping movement, the speed of 0.5mm/s, high resolution of 1μm, maximum loading capacity of 600g.

Sign in / Sign up

Export Citation Format

Share Document