scholarly journals Formulation of plastic strain distribution derived from long-distance travel of temperature distribution based on residual stress required for elastic shakedown behavior

Author(s):  
Satoshi OKAJIMA
Author(s):  
Heping Wang ◽  
Shenfeng Wu ◽  
Xueping Zhang ◽  
C. Richard Liu

To analyze AISI 52100 steel response in hard turning under pre-stressed conditions, an explicit dynamic thermo-mechanical finite element model (FEM) has been developed. The FEM adopts Johnson-Cook constitutive model to describe the workpiece material property; and Johnson-Cook failure model as chip separation criterion; a modified coulomb’s friction law determines the friction behavior at the tool/chip interface. 500MPa of tensile and compressive pre-stress are imposed on the workpiece to simulate the pre-tension-stress and pre-compression-stress conditions respectively in hard turning. The effect of pre-stress on hard turning is determined by analyzing and comparing the simulation results under the three different pr-stress conditions, in terms of saw-tooth chip morphology, cutting forces, plastic strain distribution and temperature distribution on chip, plastic strain distribution and temperature distribution in machined surface, and especially the residual stress in machined surface. It identifies hard cutting under pretension-stress condition is an effective approach to generate a beneficial compressive residual stress profile in hard turning characterized by a bigger value of compressive residual stress and a deeper penetration depth into the hard turned surface which are helpful to enhance the fatigue life of machined components.


2021 ◽  
Author(s):  
Virginia A. Fonner ◽  
David Geurkink ◽  
Faraja Chiwanga ◽  
Ismail Amiri ◽  
Samuel Likindikoki

2021 ◽  
Vol 99 ◽  
pp. 103010
Author(s):  
Jonas Åkerman ◽  
Anneli Kamb ◽  
Jörgen Larsson ◽  
Jonas Nässén

1970 ◽  
Vol 8 (2) ◽  
pp. 291-296 ◽  
Author(s):  
F Begum ◽  
RN Ali ◽  
MA Hossain ◽  
Sonia B Shahid

The study analyzed the different factors that are responsible for the harassment of women garment workers in Bangladesh. Three garment factories from Mirpur area under Dhaka district were selected purposively where garment factories are available. The sample consisted of 90 women workers taking 30 randomly from each of the three garment factories. Female workers are mostly employed at the lower category of jobs like operator, finishing helper, polyer etc. These jobs are very monotonous in nature. Because of the nature of their jobs, female workers sometimes lose interest in work and become depressed. A large number of female workers received low and irregular wages which create their job dissatisfaction. Only 22 female workers earned salary between Tk. 2700 to Tk. 3000 per month. Female workers are sexually harassed by their co-workers in the factory or by police or by mastans in the street. Communication problem is a major problem faced by most of the female garment workers. A long distance travel is not only physical strenuous but also mentally stressful. Their overtime rate is very low. Long working hours result in a number of illnesses and diseases like headache, eye trouble, ear ache, musculoskeletal pain etc. Women are exploited easily due to lack of technical knowledge and training. The employers do not pay any heed to this exploitation. Keywords: Garment industry; Women workers; Harassment DOI: 10.3329/jbau.v8i2.7940 J. Bangladesh Agril. Univ. 8(2): 291-296, 2010   


2005 ◽  
Vol 495-497 ◽  
pp. 965-970
Author(s):  
A.A. Zisman ◽  
Nikolay Y. Zolotorevsky ◽  
N.Yu. Ermakova

A rate-independent polycrystal model, allowing for the shape and spatial coordination of neighboring constitutive crystals and for the plastic strain distribution among them, has been used to simulate the local texture evolution in an Al polycrystal under compression. The simulation results compare favourably to relevant experimental data and show the reorientation path of each crystal to strongly depend on orientations of its immediate neighbors.


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