Stick-Slip Vibration Between Two Large Concentric Circular Discs in Rotational Contact With Multiple Point Loads

2003 ◽  
Author(s):  
M. Baleri ◽  
F. Sassani ◽  
P. L. Ko
Keyword(s):  
Experimental Results ◽  
Integral Model ◽  
Mathematical Representation ◽  
Multiple Point ◽  
Stick Slip ◽  
System Parameters ◽  
Modeling Simulation ◽  
Contact Loads ◽  
Simulation Results ◽  
Good Agreement

This paper presents a study of the stick-slip frictional phenomenon when large contact areas subjected to uneven contact loads are involved. The objective of the investigation is to gain better understanding of the phenomenon from experimental observations and to develop a mathematical representation that can be used for modeling, simulation and design purposes. A dynamic integral-model has been proposed and simulations have been carried out. The effects of various system parameters on the behavior of the system have been studied experimentally and analytically. The simulation results using the proposed integral-model are in good agreement with the experimental results. The latter also show that stick-slip vibrations can be influenced by the loading conditions.

Stick-Slip Vibration Between Two Large Concentric Circular Discs in Rotational Contact With Multiple Point Loads

2003 ◽  
Vol 125 (4) ◽  
pp. 786-792
Author(s):  
M. Baleri ◽  
F. Sassani ◽  
P. L. Ko
Keyword(s):  
Robotic Manipulators ◽  
Integral Model ◽  
Mathematical Representation ◽  
Multiple Point ◽  
Rotating Platform ◽  
Stick Slip ◽  
System Parameters ◽  
Modeling Simulation ◽  
Contact Loads ◽  
Good Agreement

This paper presents a study of the stick-slip frictional phenomenon when large contact areas subjected to uneven contact loads, such as the rotating platform of excavators and large robotic manipulators, are involved. The objective of the investigation is to a gain better understanding of the phenomenon from experimental observations and to develop a mathematical representation that can be used for modeling, simulation and design purposes. A dynamic integral-model has been proposed and simulations have been carried out. The effects of various system parameters on the behavior of the system have been studied experimentally and analytically. The simulation results using the proposed integral-model are in good agreement with the experimental results. The latter also show that stick-slip vibrations can be influenced by the loading conditions.

scholarly journals Numerical Simulations of V-Shaped Plates Subjected to Blast Loadings: A Validation Study

2016 ◽  
Vol 10 (11) ◽  
pp. 203
Author(s):  
Mohd Zaid Othman ◽  
Qasim H. Shah ◽  
Muhammad Akram Muhammad Khan ◽  
Tan Kean Sheng ◽  
M. A. Yahaya ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Variable Mass ◽  
Blast Loading ◽  
Experimental Results ◽  
Average Difference ◽  
Simulation Results ◽  
Blast Loadings ◽  
Carrier Vehicle ◽  
Good Agreement

A series of numerical simulations utilizing LS-DYNA was performed to determine the mid-point deformations of V-shaped plates due to blast loading. The numerical simulation results were then compared with experimental results from published literature. The V-shaped plate is made of DOMEX 700 and is used underneath an armour personal carrier vehicle as an anti-tank mine to mitigate the effects of explosion from landmines in a battlefield. The performed numerical simulations of blast loading of V-shaped plates consisted of various angles i.e. 60°, 90°, 120°, 150° and 180°; variable mass of explosives located at the central mid-point of the V-shaped vertex with various stand-off distances. It could be seen that the numerical simulations produced good agreement with the experimental results where the average difference was about 26.6%.

Manipulation of Bio-Particles by Electrokinetics

2004 ◽  
Author(s):  
Kuang Han Chu ◽  
Cheng-Hsien Liu
Keyword(s):  
Electric Field ◽  
Object Manipulation ◽  
High Electric Field ◽  
Experimental Results ◽  
Ac Electrokinetics ◽  
Modeling Simulation ◽  
Simulation Results ◽  
Electrokinetic Force ◽  
Anisotropic Etch

We propose and develop a new bio-particles manipulation device that has the similar size order as targeted bio-objects and is a non-contact approach to bio-objects using AC electrokinetics. We use micro pyramid array made by MEMS KOH anisotropic etch in our design. Simulation results using CFD-ACE+ and ANSYS show extremely high electric field around micro pyramids for our concept proof. Experimental results successfully demonstrate the feature of micro-object manipulation for our device. In this paper, we will present the design, fabrication, modeling, simulation, and testing results of our manipulation device using electrokinetic force.

Quintuple band circular monopole antenna with innovative 3-D printed PLA substrate for wireless applications

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ashraf E. Ahmed ◽  
Wael A.E. Ali ◽  
Sudipta Das
Keyword(s):  
Polylactic Acid ◽  
Monopole Antenna ◽  
Design Concept ◽  
Experimental Results ◽  
Printed Antenna ◽  
Wireless Applications ◽  
Innovative Technique ◽  
Compact Size ◽  
Simulation Results ◽  
Good Agreement

Abstract In this paper, a circular antenna with a 3-D printed substrate is introduced to achieve a multiband behavior. The circular antenna is matched using a key-shaped stub located on the perimeter of the designed antenna. The 3-DP circular antenna adopted the apollonian gasket technique to perform the multi-circular cuttings in the Polylactic Acid (PLA) substrate as an innovative technique to obtain quintuple bands. The proposed antenna is designed to operate for Bluetooth, WLAN, WiMAX, and other wireless applications in S-band and C-band. The designed antenna has a compact size of 61.1 × 43.6 × 1 mm3. The prototype of the suggested 3-D printed antenna is fabricated and measured to confirm the simulation results. A good agreement is evident between simulation and experimental results which validates the design concept.

Bond-Slip Numerical Simulation of Concrete and Gypsum Board

2011 ◽  
Vol 255-260 ◽  
pp. 3133-3136
Author(s):  
Quan Bin Zhao ◽  
Xin Liang Jiang
Keyword(s):  
Numerical Simulation ◽  
Constitutive Relation ◽  
Simulation Analysis ◽  
Experimental Results ◽  
Gypsum Board ◽  
Bond Slip ◽  
Pull Out ◽  
Simulation Results ◽  
Research Situation ◽  
Good Agreement

The characteristics and research situation of bond-slip performance at the inter face of concrete and other materials are introduced, and the bond-slip constitutive relation models are summarized at the same time. Through the load-slip curves obtained from the pull-out experiment of CFFP, the proposed bond-slip constitutive relation models are presenting, including the simple one. With the numerical simulation analysis of CFFP is carried out by the use of the proposed constitutive relation, while the numerical simulation results are in good agreement with the experimental results conducted before, which is feasible and can be applied to further research on CFFP.

Heat Transfer Investigation of an Additively Manufactured Minichannel Heat Exchanger

2019 ◽  
Author(s):  
Hamidreza Rastan ◽  
Amir Abdi ◽  
Monika Ignatowicz ◽  
Bejan Hamawandi ◽  
Poh Seng Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Single Phase ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Experimental Results ◽  
Working Fluid ◽  
Minichannel Heat Exchanger ◽  
Simulation Results ◽  
Good Agreement

Abstract This study investigates the thermal performance of laminar single-phase flow in an additively manufactured minichannel heat exchanger both experimentally and numerically. Distilled water was employed as the working fluid, and the minichannel heat exchanger was made from aluminum alloy (AlSi10Mg) through direct metal laser sintering (DMLS). The minichannel was designed with a hydraulic diameter of 2.86 mm. The Reynolds number ranged from 175 to 1360, and the heat exchanger was tested under two different heat fluxes of 1.5 kWm−2 and 3 kWm−2. A detailed experiment was conducted to obtain the thermal properties of AlSi10Mg. Furthermore, the heat transfer characteristics of the minichannel heat exchanger was analyzed numerically by solving a three-dimensional conjugate heat transfer using the COMSOL Multiphysics® to verify the experimental results. The experimental results were also compared to widely accepted correlations in literature. It is found that 95% and 79% of the experimental data are within ±10% range of both the simulation results and the values from the existing correlations, respectively. Hence, the good agreement found between the experimental and simulation results highlights the possibility of the DMLS technique as a promising method for manufacturing future multiport minichannel heat exchangers.

scholarly journals Novel Design of Electromagnetic Bandgap Using Fractal Geometry

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Huynh Nguyen Bao Phuong ◽  
Dao Ngoc Chien ◽  
Tran Minh Tuan
Keyword(s):  
Band Structure ◽  
Structural Design ◽  
Fractal Geometry ◽  
Experimental Results ◽  
Dual Band ◽  
Electromagnetic Bandgap ◽  
Unit Cells ◽  
Simulation Results ◽  
Novel Design ◽  
Good Agreement

A novel electromagnetic bandgap (EBG) structural design based on Fractal geometry is presented in this paper. These Fractals, which are the Sierpinski triangles, are arranged to repeat each 60° to produce the hexagonal unit cells. By changing the gap between two adjacent Sierpinski triangles inside EBG unit cell, we can produce two EBG structures separately that have broadband and dual bandgap. By using the suspending microtrip method, two arrays 3 × 4 of EBG unit cells are utilized to investigate the bandgap of the EBG structures. The EBG operation bandwidth of the broadband structure is about 87% and of the dual-band structure is about 40% and 35% at the center bandgap frequencies, respectively. Moreover, a comparison between the broadband EBG and the conventional mushroom-like EBG has been done. Experimental results of the proposed design show good agreement in comparison with simulation results.

Nanoindentation on a Ni Nanodot-Patterned Surface

2008 ◽  
Author(s):  
Hengyu Wang ◽  
Min Zou ◽  
Robert L. Jackson ◽  
Preston R. Larson ◽  
Matthew B. Johnson
Keyword(s):  
Finite Element ◽  
Numerical Simulations ◽  
Experimental Results ◽  
Spherical Contact ◽  
Patterned Surface ◽  
Size And Shape ◽  
Ordered Arrays ◽  
Simulation Results ◽  
Good Agreement

Nanoindentation on a Ni nanodot-patterned surface (NDPS) was investigated experimentally and numerically. The Ni NDPS consists of well-ordered arrays of Ni nanodots with approximately the same size and shape. The nanoindentation experiments were performed on the Ni NDPS using diamond tips of 1 and 5 μm radii of curvature. To efficiently simulate large number of nanodots in contact, numerical simulations were carried out using formulae empirically fitted from a finite element (FE) study of a single spherical contact. The simulation results were found to be in good agreement with the experimental results.

Integrated Flow Analysis During Filling and Post-Filling Stage of Semiconductor Encapsulation

1999 ◽  
Vol 122 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Sejin Han ◽  
K. K. Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Flow Analysis ◽  
Rectangular Cavity ◽  
Experimental Results ◽  
Molding Compound ◽  
Filling Stage ◽  
Semiconductor Chip ◽  
Simulation Results ◽  
Good Agreement

In this paper, flow during the filling and post-filling stages in semiconductor chip encapsulation has been analyzed. A finite-element method based on the Hele-Shaw approximation is used for the flow analysis in the chip cavity. The compressibility of the epoxy-molding compound has been considered to analyze the post-filling stage. The model has been verified by comparing resulting predictions with experimental results. Specifically, pressure has been measured in a rectangular cavity and compared with simulation results. The calculated and experimental results show good agreement. [S1043-7398(00)00101-8]

Desiccant Dehumidification System for Space Radiant Cooling in Tropical Climate

2012 ◽  
Vol 622-623 ◽  
pp. 1575-1579
Author(s):  
T. Kiewkem ◽  
P. Chaiwiwatworakul ◽  
S. Chirarattananon
Keyword(s):  
Computer Program ◽  
Thermal Comfort ◽  
Simulation Study ◽  
Cooling System ◽  
Tropical Climate ◽  
Experimental Results ◽  
Radiant Cooling ◽  
Simulation Results ◽  
Good Agreement

This paper presents an experimental and simulation study on application of a rotating desiccant dehumidification system under a tropical climate. The system was used to dehumidify the ventilation air before supplying to a space where a radiant cooling system was installed to provide thermal comfort. In the study, a computer program of the desiccant system was coded and used to evaluate the system performances. The experimental results show good agreement with the results from coded program. Using the program, the simulation results demonstrate that the desiccant system can reduce and handle the load of the ventilation air. The results also show that in order to remove the whole latent load, the minimum regeneration temperature is 80°C.

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