Mechanical Elements ofFracture Fracture and DamageDamage

2017 ◽  
pp. 217-250
Author(s):  
Christian Lexcellent
Keyword(s):  
Mechanical Elements

Observation of Fatigue Fracture on PEEK Shaft against Alumina Bearing’s Ball under One-Point Rolling Contact

2016 ◽  
Vol 878 ◽  
pp. 137-141 ◽  
Author(s):  
Hitonobu Koike ◽  
Genya Yamaguchi ◽  
Koshiro Mizobe ◽  
Yuji Kashima ◽  
Katsuyuki Kida
Keyword(s):  
Fatigue Fracture ◽  
Rolling Contact Fatigue ◽  
Rolling Direction ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Hertzian Contact ◽  
Subsurface Crack ◽  
Mechanical Elements ◽  
The One ◽  
Alumina Ball

Tribological fatigue failure of the machined PEEK shaft was investigated through the one-point type rolling contact fatigue test between a PEEK shaft and an alumina ball, in order to explore fatigue fracture mechanism of frictional parts working at high frequency in various mechanical elements. Due to Hertzian contact of cyclic compressive stress, the subsurface crack occurred within approximately 300 μm depth from thesurface and propagated along the rolling direction. After that, the subsurface crack propagation direction changed toward the surface. The flaking occurred on the raceway of the PEEK shaft when the subsurface crack reached to the PEEK shaft surface.

EXPERIMENTAL STUDY OF FREQUENCY PROPERTIES OF MECHANICAL ELEMENTS WITH DISTRIBUTED PARAMETERS

2013 ◽  
pp. 112-119
Author(s):  
Vladimir Tadeushevich Vishnerevsky ◽  
Igor Sergeyevich Stasenko ◽  
Gennady Sergeyevich Lenevsky ◽  
Aleksey Anatolyevich Korneyev
Keyword(s):  
Experimental Study ◽  
Distributed Parameters ◽  
Mechanical Elements ◽  
Frequency Properties

scholarly journals Constructiv and Technological Consideration on the Generation of Gear Made by the DLP 3D-Printed Methode

2019 ◽  
Vol 56 (2) ◽  
pp. 440-443
Author(s):  
Mircea Dorin Vasilescu
Keyword(s):  
Optical Microscope ◽  
Functional Domain ◽  
Conserved Quantities ◽  
Technological Parameters ◽  
Specific Design ◽  
Domain Specific ◽  
Cylindrical Gears ◽  
3D Printed ◽  
Mechanical Elements ◽  
The Cost

The aim of the work is conduct to highlight how the technological parameters has influence of 3D printed DLP on the generation of wheel, made from resin type material. In the first part of the paper is presents how to generate in terms of dimensional aspects specific design cylindrical gears, conical and worm gear. Generating elements intended to reduce the cost of manufacturing of these elements. Also are achieve the specific components of this work are put to test with a laboratory test stand which is presented in the paper in the third part of the paper. The tested gears generated by 3D-printed technique made with 3D printed with FDM or DLP technique. After the constructive aspects, proceed to the identification of conserved quantities, which have an impact both in terms of mechanical strength, but his cinematic, in order to achieve a product with kinematic features and good functional domain specific had in mind. The next part is carried out an analysis of the layers are generated using the DLP and FDM method using an optical microscope with magnification up to 500 times, specially adapted in order to achieve both visualization and measurement of specific elements. In the end part, it will highlight the main issues and the specific recommendations made to obtain such constructive mechanical elements.

scholarly journals Safe Joint Mechanism using torsion springs for Collision Safety and Positioning Accuracy of a Robot Arm

2020 ◽  
Author(s):  
Adel Belharet ◽  
Jae-Bok Song
Keyword(s):  
Service Robots ◽  
Robot Arm ◽  
Positioning Accuracy ◽  
External Torque ◽  
High Stiffness ◽  
Collision Safety ◽  
Passive Compliance ◽  
Joint Mechanism ◽  
Mechanical Elements ◽  
Torsion Springs

In recent years, the potential for collision between humans and robots has drawn much attention since service robots are increasingly being used in the human environment. A safe robot arm can be achieved using either an active or passive compliance method. A passive compliance system composed of purely mechanical elements often provides faster and more reliable responses to dynamic collision than an active system involving sensors and actuators. Since positioning accuracy and collision safety of a robot arm are equally important, a robot arm should have very low stiffness when subjected to a collision force capable of causing human injury. Otherwise, it should maintain a very high stiffness. To implement these requirements, a novel safe joint mechanism (SJM-IV) consisting of a CAM, rotational links with rollers, and torsion springs is proposed. The SJM-IV has the advantage of nonlinear stiffness, which can be achieved only with passive mechanical elements. Various analyses and experiments on static and dynamic collisions show high stiffness of the SJM-IV against an external torque less than a predetermined threshold torque, with an abrupt drop in stiffness when the external torque exceeds this threshold. The safe joint mechanism enables a robot manipulator to guarantee positioning accuracy and collision safety, and which is simple to install between an actuator and a robot link without a significant change in the robot’s design.

scholarly journals Non-Conventional Actuation Mechanisms used in Mechatronic systems

2018 ◽  
Vol 3 (1) ◽  
pp. 05-10
Author(s):  
Rajiv Chaudhary ◽  
◽  
Alok Kumar Singh
Keyword(s):  
Mechanical Systems ◽  
Recent Past ◽  
Mechatronic Systems ◽  
Actuation System ◽  
Prime Movers ◽  
Overall Performance ◽  
Engine System ◽  
Mechanical Elements ◽  
Actuation Systems ◽  
Mechanical Actuation

Tracking the path of development in different Engineering disciplines, it can be easily observed that, right from the primitive stage, several tools, devices, and techniques may be identified, which happened by virtue of the evolution of human intelligence, getting transformed into various engineering applications. Although, later different engineering disciplines evolved, where most of the exhaustive development could be undertaken in that discipline. Likewise, in the field of mechanical engineering to various types of mechanical systems, according to the requirement in that field, were developed, in order to provide support of mechanization. Prime movers used to be an important part of these mechanical systems, which provided energy input as well as actuation required for providing the machines the desired kinematics. Most of the mechanical systems developed has been operated by conventional engine system using one or other fuel. Apart from the actuation by mechanical means, there are other means also through which mechanical actuation with better control, flexibility, and manipulation may be utilized in mechanical systems. A different category of systems, called Mechatronic systems has been developed in the recent past, which involves the vivid scope of use of techniques, devices, and components generally used in various other engineering fields of electrical, electronics, hydraulics, and pneumatics, etc. Subsequently, there have been several inventions, design & development which have added new levels in every field. Mechanical systems have been generally composed of various mechanical elements, which are designed to follow certain kinematics. The performance of the Actuation system plays an important role in the overall performance of the mechanical systems. There are several alternative actuation systems, which are not mechanical. These actuation systems may be categorized into electrical, electronics, hydraulic and pneumatic types. The features of these actuation systems, are so peculiar, that typical kinematic movement may be manipulated that too with more precision. Better control of mechanical systems may be realized, which is otherwise difficult with mechanical systems. In this paper, an effort has been made to review the possibilities, prospects as well as scope with various actuation systems.

Simulation of a Differential-Drive Wheeled Mobile Lego Robot Mindstorms NXT

2015 ◽  
Vol 776 ◽  
pp. 319-324
Author(s):  
I. Wayan Widhiada ◽  
C.G. Indra Partha ◽  
Yuda A.P. Wayan Reza
Keyword(s):  
Mobile Robot ◽  
3D Model ◽  
Hardware Implementation ◽  
Movement Control ◽  
Common Environment ◽  
Matlab Simulink ◽  
Differential Drive ◽  
Simulation Results ◽  
Mechanical Elements ◽  
Drive Model

The aim of this paper is to model and simulate kinematics motion using the differential drive model of a mobile Lego robot Mindstorm NXT. The author’s use integrated two software as a method to solve the simulation of mobile lego robot mindstorms NXT using Matlab/Simulink and Solidworks software. These softwares are enable easier 3D model creation for both simulation and hardware implementation. A fundamental of this work is the use of Matlab/Simulink Toolboxes to support the simulation and understanding of the various kinematics systems and in particular how the SimMechanics toolbox is used to interface seamlessly with ordinary Simulink block diagrams to enable the mechanical elements and its associated control system elements to be investigated in one common environment. The result of simulation shows the mobile robot movement control based on decentralized point algorithm to follow the precision x and y references that has been specified. The design of the mobile robot is validated in simulation results as proof that this design can achieve the good performance.

Experimental investigations on surface finish and microgeometry of helical gear in pulsed-electrochemical honing process

2019 ◽  
Vol 233 (10) ◽  
pp. 3364-3375 ◽  
Author(s):  
Pravin Rai ◽  
Neelesh K Jain ◽  
Sunil Pathak
Keyword(s):  
Surface Finish ◽  
Removal Rate ◽  
Experimental Investigations ◽  
Helical Gears ◽  
Mechanical Parts ◽  
Sandwich Type ◽  
Mechanical Elements ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

Gear is one of the most vital mechanical elements for transmission of power and motion. It has been considered as one of the highest consumable mechanical parts. Surface attributes of the gears are most important elements to describe its operating performance, service life, and accuracy. Present work highlights the development of pulsed-electrochemical honing process to enhance the performance of gears by refining the variables of surface roughness, microgeometry, and material removal rate of 20MnCr5 alloy steel helical gears. Freshly designed sandwich type cathode gear has been developed which served as a tool in pulsed-electrochemical honing process. Investigations have been done on studying the effects and identifying the optimum values of four most important variables of pulsed-electrochemical honing process, namely applied voltage ( V), pulse-on time ( T on), pulse-off time ( T off), and finishing time ( t) on synchronized enhancement in surface finish and microgeometry. Results of the investigations reveal that T on as 6 ms, T off as 3 ms, t as 8 min, and V as 16 V yielded the best results for surface finish and microgeometry together.

Sign in / Sign up

Export Citation Format

Share Document