In end milling operation, cutting forces induce vibration on tool, work piece and clamping devices which affects surface integrity and quality of the product. In this process, to select the optimum end mill and machine tool, the prediction of exact cutting forces is of prime importance. In the present work, modeling and simulation of cutting forces in end milling operation are performed. Instantaneous chip geometry is predicted using a 3D simulation software, the effect of cutting depth and feed rate are calculated and cutting conditions are predicted before any machining operation.

There are two approaches for simulating memory as well as learning in artificial intelligence; the functionalistic approach and the cognitive approach. The necessary condition to put the second approach into account is to provide a model of brain activity that contains a quite good congruence with observational facts such as mistakes and forgotten experiences. Given that human memory has a solid core that includes the components of our identity, our family and our hometown, the major and determinative events of our lives, and the countless repeated and accepted facts of our culture, the more we go to the peripheral spots the data becomes flimsier and more easily exposed to oblivion. It was essential to propose a model in which the topographical differences are quite distinguishable. In our proposed model, we have translated this topographical situation into quantities, which are attributed to the nodes. The result is an edge-weighted graph with mass-based values on the nodes which demonstrates the importance of each atomic proposition, as a truth, for an intelligent being. Furthermore, it dynamically develops and modifies, and in successive phases, it changes the mass of the nodes and weight of the edges depending on gathered inputs from the environment.

Surface roughness is one of the most important characteristics in nanomachining products. One of the parameters that always has a great impact on the surface quality is the forces caused by the nanocutting process. In this research, using molecular dynamics simulation in LAMMPS software, the process of dynamic nano ploughing of single-crystal copper workpiece by a diamond tool is investigated. The effect of parameters of dynamic nano- ploughing process such as depth of cut, amplitude and frequency of cutting tool vibration on cutting force and surface roughness has been investigated by calculating average roughness. Also, in order to more closely examine the effect of parameters and their interaction on each other, Taguchi method has been used to design experiments. The simulation results show that the characteristics of cutting depth, amplitude and frequency of cutting tool vibration have the greatest effect on surface smoothness and cutting forces, respectively. Based on the presented results, it has been determined that the surface roughness can be improved in different machining conditions based on the selection of parameters, and it is necessary to check their conditions together well before selecting these parameters. Also, using Taguchi method, the optimal values of dynamic ploughing parameters were obtained to achieve the best surface smoothness and the lowest cutting force in certain dimensions as described by DOC=2.5 , R=0.1 and ω=50 KHz.

Damage of metals is a progressive physical process which finally leads to the failure of them. In this study, first, a coupled elastic- plastic- Lemaitre's ductile damage model combined with large deformations theory is developed and implemented as a subroutine into ABAQUS/EXPLfCIT code. Then, by performing standard tensile and Vickers micro-hardness tests, mechanical and damage properties for St 14 steel are determined. For validation of the damage model and also identified properties, cutting and fine cutting processes are simulated by the model in two cases of large and small deformation theories. Comparison of the numerical simulation results and experimental reports show that Lemaitre's ductile damage model combined with large deformation theory can accurately predict damage evolution, crack initiation, propagation, and ductile fracture in the metal forming processes with large deformations.

One of the most advanced methods of cutting materials is water jet cutting. Due to its advantages over other cutting methods, it has been widely used in recent years. Cutting with a water jet is a subset of fluid and structure interaction issues in which water flows into the boundaries of the rock, and this changes the shape of the rock in the impact area. In order to examine this issue accurately, the boundary conditions of water and rock must be coupled in order to obtain the correct behavior of the collision area, which is the most important and complex part of simulation by theoretical, experimental and numerical methods. In this paper, the rock cutting with water jet is simulated using a smoothed particle hydrodynamics method, which is a lagrangian numerical and meshfree method. For this purpose, firstly, the governing equations for fluid and solid are discretized with the help of the predictive-correct algorithm. Then, using the algorithm based on these equations, two-dimensional collision of water jet and rock and breaking behavior of rock are simulated. With this method, the depth and width of the cut can be determined at different speeds of the water jet and the optimal cutting speed of the stone is obtained. The results of the simulation have acceptable accuracy compared to the experimental results and shows that the smoothed particle hydrodynamics method is a suitable method for the analysis of rock cutting with water jet.

A model has been developed for unsteady-state simulation of non isothermal, gas absorption with chemical reaction in packed columns. The model is based upon the two film theory in each time step and finite difference technique is used to solve the governing system of partial differential equations. The constructed model is capable to predict the concentration of all components in both gas and liquid phases as well as the temperature of each phase along the bed in dynamic and the final steadystate. Results of the model, subjected to various forcing functions were compared with the experimental data obtained from a pilot-plant gas absorption unit, where CO2 was removed from an AIR--- CO2 mixture into an aqueous monoethanolamine (MEA) solution.

In order to help in the engineering design of rice harvesting machines, there is a need to have exact information concerning the physical and mechanical properties of rice stems. The cutting force for rice stems, therefore, was measured by designing and fabricating a static and dynamic shear test apparatus. The effects of moisture levels and the crosssectional area of stem as well as the variety, blade bevel angle, blade type and cutting speed on shearing strength have been evaluated. The results indicated that the cutting force increased with an increase in the cross-sectional area and decreased with an increase in moisture content. The static and dynamic shearing strength was different among the varieties. The maximum and minimum shearing strengths were related to the varieties Khazar and Hashemi, with an average of 1629 and 1429 kPa for static test and values of 187.4 and 144 kPa for the dynamic test, respectively. The shearing strength decreased from 234.4 kPa to 137.4 Kpa with an increase in blade cutting speed from 0.6 to 1.5 m/s. Blade bevel angle and blade type had no significant effect on the shearing strength of rice stem.

The built up layer thickness in secondary deformation zone is one of the important parameters in metal cutting process. The built up layer (BUL) is formed in second deformation zone near the tool-chip interface in the back of the chip. This parameter influences the tool life and machined surface quality. This BUL should not be confused with the built up edge (BUE). The deformation of the BUL in the secondary shear zone is a stable and continues process; leading to an uniform thickness of the BUL along the chip's back but the deformation of the BUE is an unstable process in front of the tool edge. Numerical simulation is a suitable method for determination of temperature, stress and strain distribution in metal cutting since it dose not suffer the analytical methods limitations and experimental methods cost. In this paper a new method is presented to calculate the built up layer thickness in secondary deformation zone using finite element simulation of orthogonal metal cutting process. There are two main concepts about chip separation mechanisms from work piece, i.e. crack propagation and pour deformation without crack. In the present work chip formation process is assumed as a pour plastic deformation, considering second chip separation mechanism. There is no separation criterion in the simulations based on pour deformation, but Adaptive remeshing is performed during simulation to avoid the difficulties associated with deformation induced element distortion. An updated Lagrangian finite element model of two dimensional orthogonal cutting process is developed. This model is meshed using 4-node plain strain elements. Thermo-mechanical coupled analysis, with adaptive remeshing is performed by LS-DYNA finite element code. Johnson-Cook material model is used for determination of the work piece material flow stress and the cutting tool is assumed as a rigid body. An updated coulomb friction law is used to describe friction condition in tool-chip interface. The temperature and equivalent strain distribution diagrams in cutting zone are shown at various cutting speeds. The built up layer thickness in various cutting speed are also calculated by equivalent strain gradient in second deformation zone. The numerical calculated tool average temperatures and the built up layer thicknesses in various cutting speeds are compared with the experimental data given in literature and good agreement is observed between them.

Summary: This study is to simulate the rock fragmentation process with disc cutter in linear cutting machine (LCM) using the numerical method of finite element. The numerical model of rock and disc cutter was built according to the experimental settings, and then, validated with the test data. The rock model was built for Indiana Limestone as it was used in experimental study. The comparison of cutting forces obtained from the numerical simulation with those obtained from LCM test showed a good agreement between the simulation and the test results.Introduction: Use of tunnel boring machine (TBM) for hard rock tunneling has been ever increased due to the growth of technology and society, as well as growing demand. The main role of disc cutters in this machine is rock cutting. An accurate estimation of the forces acting on the disc cutter is very important in machine design. To do so, the cutting forces acting on a single disc cutter as well as its performance in a specific rock are predicted using full-scale linear rock cutting tests. The results are then generalized for TBM design in the same rock.Methodology and Approaches: The commercial finite element code ABAQUS/CAE was used to perform the numerical simulations of the rock cutting process in LCM test. The forces acting on a fresh constant cross section disc and specific energy were simulated. For validation purposes, the results obtained from numerical model were compared with those of experimental results.Results: and Conclusions The model validity was checked by comparing the results recorded from the experiments and those results obtained from numerical simulation. All cutting forces obtained from simulation were located in the confidence interval of experimental data. The analysis results showed that cutting forces and cutting coefficient increased non-linearly with increasing disc penetration. A good agreement was obtained between the numerical results and experimental data. Moreover, the cutting forces obtained from the simulation showed a maximum deviation of 15 and 21% from the experimental average values for normal force in penetration depth of 5 mm and rolling force in 2.5 mm, respectively.