Simulation of Plastic Strain and Plastic Strain Rate in Turning Operation of AISI 4340 Steel using Finite Element Method

This paper presents an influence of feed rate on plastic strain and plastic strain rate during high speed machining (HSM) operation of AISI 4340 Steel using Johnson-Cook flow curve constitutive equation combine with Coulomb friction model in order to obtain plastic strain distribution and plastic strain rate via finite element method. The result shows that plastic strain occurs more on the outer side of the chip than on the inner side of the chip. The values of plastic strain and plastic strain rate are found to have variation with the feed rate investigated in this study.

Production of Vacuum-formed Retainer for Orthodontics by Computer-aided Engineering

In dental treatment, Retainer is a dental equipment for all patients to keep their teeth after bracing from changing position. There are2 types of Retainers, brace retainer and vacuum-formed retainer (VFRs). It looks like a clear plastic and hard to notice when wearing. But the VRFs was made by handmade. It takes a long time to produce and has higher prices than other types of retainer.

3D Printing technology is a new alternative to form the material, which is process by computer command and filling the material layer by layer to get the material according to the required shape.This technology is very useful in the industry.

This project presents the production of vacuum-formed retainer by 3D Printing and comparing the wear resistance of various materials used for VFRs by mastication test. Stereo microscope pictures are useful for examining the surface of VFRs. The results show that retainer produced by 3D Printing has no similar properties asVFRs by normal production, not tolerant from impact and not resistance of chewing, can not be used, and not safe for patients.

In Vivo Measurements of the Mechanical Properties of Human Skin and Muscle by Inverse Finite Element Method Combined with the Indentation Test

Biomechanical properties of human skin and muscle are important in several domains, particularly for impact biomechanics, rehabilitation engineering and sports science. However, the mechanical behavior of human skin and muscle in compression remains poorly characterized. Thisstudy proposed a new method to determine mechanical properties of human skin and muscle by inverse finite element method combined with the indentation test. The nonlinear property of human skin and muscle was best suited by Jamus-Green-Simpson strain energy function. Parameters of equation could directly be applied in the available material properties in MSC.Marc 2008 – a finite element analysis (FEA) software. The parameters of the equation were obtained from trial and error by using the FEA software. The force-displacement relation from FEA was compared with the experiment; the average error was 0.34 %.

Finite Element Analysis of New-era Roller Skate

The conception designs of New-era Roller Skate are outline urban solutions to environment, accident and traffic. Finite element analysis is a tool used for the strength evaluation of 3D components skate such as gripper, truss, drive pinion and shaft. The aim of this study to analyses available load, stress and skate deformation to save time and save cost pre-production prototypes. The results of simulation show that New-era Roller Skate could actually use this boundary condition and safe all the time.

Influence of Hot Air Welding Parameters for Architecture Canvas

Many parameters affect to the strength of joint welded by hot air welding. The objective of this research is to investigate the effect of space of probe temperature torque and speed of welding on the strength of canvas welded area joined by hot air welding. The experiment is lab joint welded of width 3 millimeter and 8 millimeter length. The welded 625 specimens are subsequenced to tensile test to determine their strengths. The result show that the factor of temperature and torque are positively correlated with the strength of canvas welded area joined. On the other hand, the factor of speed of welding is inversely with the strength of canvas welded area joined. All parameters are explain the variability of the strength of the weld was 81.37 % at the reliability level 95 %.

Responsibility

Khomgris Chaiyo, Ph.D.