Finite element modeling has been used to study the development of surface deformation during indentation with a Vickers indenter. A wide range of materials with different elastic modulus and yield stresses are examined. Results show that in a pyramidal indentation process, for a perfectly plastic material, sinking-in during loading can change to pile-up in unloading. This phenomenon depends on ...

for dynamic analyses of railway track structures, the algorithm of solution is very important. for estimating the important problems in the railway tracks such as the effects of rail joints, rail supports, rail modeling in the nearness of bridge and other problems, the models of the axially beam model on the elastic foundation can be utilized. for studying the effects of axially beam on the ela...

In this paper a three-dimensional finite element (FE) model of carbon nanocones (CNCs) is proposed and used for obtaining Young\'s modulus of CNCs. In this model, stretching and bending forces between carbon atoms are simulated using truss elements in ANSYS software. Then the model is subjected to the tension and by obtaining the stiffness of the CNC and using elasticity theory, Young’s modulus...

We study the wage structure during economic transition in the context of Chinese cities and examine the effect of China’s urban housing reforms on the urban wage structure (1988-2005). We find that these reforms, which untied access to housing from state-sector employment, shifted approximately 17% of the labor force from the state sector to the private sector, increasing the private sector lab...

China’s college admission rose from one million in 1998 to seven million in 2009, and associated with the expansion is the declining college premium for young workers. However, the college premium for senior workers increased in the same period. We show that the rising demand for skilled workers is the driving force. To explain this, we build a general equilibrium theory that considers two dime...