scholarly journals Simulating the Effect of Friction on Drive Screw Using System-of-System Modeling with Predetermined Torque

2021 ◽  
Author(s):  
Fatima Isiaka ◽  
Awwal M. Adamu ◽  
Salihu A. Abdulkarim ◽  
Abdullahi Salihu
Keyword(s):  
System Approach ◽  
System Modeling ◽  
Screw Thread ◽  
Bolt Preload ◽  
Simple Simulation ◽  
Simulation Scenario ◽  
The Coefficient Of Friction ◽  
Drive Screw ◽  
Screw Threads ◽  
And Behavior

In most mechanical systems, screw threads serve three main basic purposes: (i) to transmit power, (ii) to provide a clamping force, and finally (iii) to restrict or control motion. This chapter demonstrates the effects of friction and behavior which can occur in a bolted fastening (screw thread) for advanced design purposes. To model this behavior, other control components are attached to the bolted screw. The bolt preload is applied with a predetermined torque. For this case the preload depends on the friction under the head and in the thread. The friction prevents the loosing of the bolted fastening. This effect is termed as self-locking effect. We designed an algorithm that reproduces an exemplary simulation scenario, which determines friction and its effect on thread angle based on the strength of the coefficient of friction at a specific tension or clamp load value using the system-of-system approach. The result shows specific behavior on both the motion in threads and drive screw with predetermined torque. The chapter is limited to creating a simple simulation environment to demonstrate the effects.

Object-Process Methodology Applied to Modeling Credit Card Transactions

2002 ◽  
pp. 87-105
Author(s):  
Dov Dori
Keyword(s):  
Supply Chain ◽  
Supply Chain Management ◽  
Electronic Commerce ◽  
Credit Card ◽  
Formal Model ◽  
System Modeling ◽  
Chain Management ◽  
Before And After ◽  
Process Methodology ◽  
And Behavior

Object-Process Methodology (OPM) is a system development and specification approach that combines the major system aspects–function, structure and behavior–within a single graphic and textual model. Having applied OPM in a variety of domains, this chapter specifies an electronic commerce system in a hierarchical manner, at the top of which are the processes of managing a generic product supply chain before and after the product is manufactured. Focusing on the post-product supply chain management, we gradually refine the details of the fundamental, almost “classical” electronic commerce interaction between the retailer and the end-customer, namely payment over the Internet using the customer’s credit card. The specification results in a set of Object-Process Diagrams and a corresponding equivalent set of Object-Process Language sentences. The synergy of combining structure and behavior within a single formal model, expressed both graphically and textually, yields a highly expressive system modeling and specification tool. The comprehensive, unambiguous treatment of this basic electronic commerce process is formal, yet intuitive and clear, suggesting that OPM is a prime candidate for becoming a common standard vehicle for defining, specifying, and analyzing electronic commerce and supply chain management systems.

Screws and Screwing

1951 ◽  
Vol 164 (1) ◽  
pp. 52-67
Author(s):  
C. Eatough
Keyword(s):  
Simple Formula ◽  
Mathematical Treatment ◽  
Screw Thread ◽  
Thread Profile ◽  
Tool Profile ◽  
Wide Range ◽  
Screw Threads

The paper describes the various commercial methods of producing screw threads by cutting, rolling, grinding, and milling. The operating principles on which the several processes depend are dealt with and their advantages and limitations are discussed. A workshop method of determining the torque required for tapping and for threading is described, and a chart based on the results gives figures suitable for determining the power of machines to undertake the tapping or screwing of a wide range of work. A mathematical treatment of the clearance between the flanks of a tool and a screw thread is given. This permits the investigation of clearances at any point on the tool profile or flank, and enables relief and tilt angles to be chosen to suit various conditions of lead, thread profile, and diameter for both internal and external threads. For design purposes, a simple formula is available which gives clearance angles in relation to the portions of the tools most subject to interference.

Effects of Nut Thinning due to Corrosion on the Strength Characteristics and the Sealing Performance of Bolted Flange Joints Under Internal Pressure

2011 ◽  
Author(s):  
Tsutomu Kikuchi ◽  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Yield Stress ◽  
Strength Characteristic ◽  
Small Scale ◽  
Screw Thread ◽  
Flange Joint ◽  
Bearing Surface ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Screw Threads

The effects of nut thinning due to corrosion on the strength characteristic and the sealing performance in 3B bolted flange joints under internal pressure are examined from both FEM calculations and experiments. The following results are obtained. When bolts and nuts in a bolted flange joint are tightened with 50% of yield stress, no yield region at the engaged screw thread occurs, however, when they arc tightened with 90% of the yield stress, a small scale yield region occurs at the roots of the engaged three screw threads from the bearing surface of the nut. While verifying this phenomenon using FEM, it was newly discovered that when the height of the nut was reduced to 1/3 (equivalent to approximately two threads) of the original dimensions according to the standards, the sealing performance could no longer be assured.

scholarly journals Examination of a Low-Profile Spinal Implant

2017 ◽  
Vol 11 (6) ◽  
pp. 895-901
Author(s):  
Takuto Iwade ◽  
Noriyuki Hisamori ◽  
Junichi Fujita ◽  
Kenji Yamaya ◽  
◽  
...  
Keyword(s):  
Contact Area ◽  
Cyclic Load ◽  
Load Test ◽  
Screw Thread ◽  
Static Load Test ◽  
Spinal Implant ◽  
Thread Surface ◽  
Low Profile ◽  
Screw Threads

Most spine implant devices are fabricated outside Japan, and therefore do not always fit the bodies of Japanese people. This causes a quality-of-life (QOL) problem in which patients feel the embedded implant devices on their back. The aim of this study was to develop more compact and lower-profile spine implant devices. Three types of devices with different heights and different screw threads were created, and the removal torque (fitting force) of the devices was measured after a static load test and cyclic load test. In addition, the screw thread surface was observed in detail after the tests. The results indicated that the mechanism of the reduction in the fitting force was related to partial contact due to abrasion or plastic deformation of the screw thread surface and decrease in the contact area between the screw threads caused by the increased diameter of the upper opening of the implant device after tightening. Therefore, we concluded that lowering the height of the implant device, securing the number of the screw threads, and securing the contact area of the threads are important in developing a low-profile spine implant.

scholarly journals Visuo-Haptic Mixed Reality Simulation Using Unbound Handheld Tools

2020 ◽  
Vol 10 (15) ◽  
pp. 5344
Author(s):  
Mehmet Murat Aygün ◽  
Yusuf Çağrı Öğüt ◽  
Hulusi Baysal ◽  
Yiğit Taşcıoğlu
Keyword(s):  
Mixed Reality ◽  
Real Life ◽  
General Purpose ◽  
Virtual Object ◽  
Tennis Ball ◽  
Real Scene ◽  
Simple Simulation ◽  
Kinesthetic Feedback ◽  
Simulation Scenario ◽  
Torque Transducer

Visuo-haptic mixed reality (VHMR) adds virtual objects to a real scene and enables users to see and also touch them via a see-through display and a haptic device. Most studies with kinesthetic feedback use general-purpose haptic devices, which require the user to continuously hold an attached stylus. This approach constrains users to the mechanical limits of the device even when it is not needed. In this paper, we propose a novel VHMR concept with an encountered-type haptic display (ETHD), which consists of a precision hexapod positioner and a six-axis force/torque transducer. The main contribution is that the users work with unbound real-life tools with tracking markers. ETHD’s end-effector remains inside the virtual object and follows the tooltip to engage only during an interaction. We have developed a simulation setup and experimentally evaluated the relative accuracy and synchronization of the three major processes, namely tool tracking, haptic rendering, and visual rendering. The experiments successfully build-up to a simple simulation scenario where a tennis ball with a fixed center is deformed by the user.

A SysML based hybrib photovoltaic-wind power system model

2017 ◽  
Vol 1 (2) ◽  
pp. 1
Author(s):  
Doudou Nanitamo Luta ◽  
Atanda K. Raji
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Power ◽  
Systems Engineering ◽  
System Modeling ◽  
Point Of View ◽  
Modeling Language ◽  
Wind Power System ◽  
And Behavior ◽  
Model Based Systems Engineering

This paper presents a model of hybrid photovoltaic-wind power system based on SysML (System Modeling Language) which is a modeling language in supports to Model Based Systems Engineering (MBSE) practices. MBSE refers to a formalized procedure of systems development through the application of modeling principles, methods, languages and tools to the complete lifetime of a system.  Broadly speaking, the modeling of power systems is performed using software such as Matlab/Simulink, DigSilent, PowerWorld, ETAP, etc. These tools allow modeling considering a particular point of view depending on the objective that is to be assessed. SysML offers different aspects ranging from specifications and requirements, structure and behavior. This study focuses more specifically on the structural and behavioral modeling of hybrid photovoltaic-wind system; the main objective is to demonstrate the use of SysML in power systems’ modeling by developing models capturing the system’s major requirements, the structure and connection between entities, the interaction between stakeholders and the system itself and lastly, the system’s behavior in terms of transition between states.

3-D FEM Stress Analysis of Screw Threads in Bolted Joints Under Static Tensile Loadings

2014 ◽  
Author(s):  
Shunichiro Sawa ◽  
Mitsutoshi Ishimura ◽  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Plastic Deformation ◽  
Bolted Joints ◽  
Experimental Result ◽  
Screw Thread ◽  
Numerical Result ◽  
Static Tensile ◽  
Hollow Cylinders ◽  
Stress States ◽  
Plastic Deformation Region ◽  
Screw Threads

The stress concentration factor (SCF) for the roots of screw threads in bolted joints under static loadings is analyzed using 3-D elastic FEM taking account the spiral of screw threads. At first, the stress states at the roots of screw threads in initial clamping state in a bolted joint where two hollow cylinders were clamped with a bolt and a nut were analyzed in initial clamping. The elastic FEM result of SCF for the first root was obtained as SCF=3.2. When the bolt was clamped in initial clamping (preload) at the 60 % of bolt yield stress, the plastic deformations were found at the first and the second roots, and non-engaged screw threads. It was found that as the external tensile loads increased, the development in plastic deformation region increased from the first root to the other roots as well as the non-engaged screw threads. It was found that the rupture occurred from the non-engaged screw threaded part while the plastic deformation increased at each root of screw threads. The numerical result was coincided with the experimental result. In the experiments, it was observed that the rupture occurred from the non-engaged screw thread and not from the first root of screw thread. Also, the bolt fatigue was predicted from FEM and it was shown that a fatigue fracture occurred from the first root.

Optimal Design of Triangle Fastening Screw Thread's Turn Number

2011 ◽  
Vol 314-316 ◽  
pp. 657-660
Author(s):  
Jian Min Chen ◽  
Meng Zhang ◽  
Jia Deng
Keyword(s):  
Optimal Design ◽  
Research Method ◽  
Equivalent Stress ◽  
Coupled Model ◽  
The Other ◽  
Screw Thread ◽  
Ansys Software ◽  
Axial Pressure ◽  
Maximum Equivalent Stress ◽  
Screw Threads

The paper firstly numerically simulates the coupled model of triangle fastening screw threads in the application of ANSYS software. Calculate stress intensity of the screw thread on the axial pressure of 200MPa. The fittest coupled turn number of the screw nut is designed to make sure the strength of coupled teeth and make every turn of the screw thread go on very well and also save material. The maximum equivalent stress of the screw thread changes linearly with the axial pressure. The stress of the thread's root is greater than that of the thread's top so that the root is easily damaged. The paper's research method can apply to the optimal design of the other patterns of screw thread's turn number.

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