Using a fractal model, we give a new interpretation of the reversed sigmoidal curves of fracture surface profile length obtained in some experiments. It is pointed out that a single parameter (fractal dimension D) is ...Using a fractal model, we give a new interpretation of the reversed sigmoidal curves of fracture surface profile length obtained in some experiments. It is pointed out that a single parameter (fractal dimension D) is not sufficient to characterize a fractal curve completely. It is shown that the initiator length L-0 is also important to characterize a fractal curve. We have derived a formula which correlate the fracture energy with the fractal parameters of the fracture surfaces and analyzed some experimental data.展开更多
We have theoretically analysed the perimeter-area relation and simulated its application to measuring the fractal dimension of fracture surfaces. It is proved that the fractal dimension D obtained by slit island metho...We have theoretically analysed the perimeter-area relation and simulated its application to measuring the fractal dimension of fracture surfaces. It is proved that the fractal dimension D obtained by slit island method (SIM) is related to the dependence of measured area A(delta) of the slit island on yardstick delta. So in some cases, the dimension D obtained by SIM is dependent on yardstick and in other cases independent on yardstick delta. But in all cases, when delta-->0 the dimension D obtained by SIM approaches the real fractal dimension (similar dimension) of 'coastline' of the island. We analysed some experimental data and found some new and interesting characteristics of crack propagation in steels.展开更多
Length-yardstick relation was used for measurement of the fractal dimension and the length of the initiator of Koch curves. It was found that the higher the fractal dimension and then the fracture toughness, the short...Length-yardstick relation was used for measurement of the fractal dimension and the length of the initiator of Koch curves. It was found that the higher the fractal dimension and then the fracture toughness, the shorter the length of the initiator of the Koch curve for the crack lines would be.展开更多
A simple parameterization of embedded atom method is proposed and two adjustable parameters are introduced to describe the pairwise potential and electron density. The embedded energy functions are obtained for fee me...A simple parameterization of embedded atom method is proposed and two adjustable parameters are introduced to describe the pairwise potential and electron density. The embedded energy functions are obtained for fee metals Cu, Ag, Au, Ni, Pd and Pt through the standard fitting procedure of embedded atom method. To test the validity of the obtained functions, the formation energy of various defects are calculated.展开更多
The present paper has studied the effects of dislocation density on the role of edge and screw dislocations and described further the parallel feature of the edge and screw dislocations and their role on the plastic d...The present paper has studied the effects of dislocation density on the role of edge and screw dislocations and described further the parallel feature of the edge and screw dislocations and their role on the plastic deformation of metals.展开更多
Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the impo...Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.展开更多
文摘Using a fractal model, we give a new interpretation of the reversed sigmoidal curves of fracture surface profile length obtained in some experiments. It is pointed out that a single parameter (fractal dimension D) is not sufficient to characterize a fractal curve completely. It is shown that the initiator length L-0 is also important to characterize a fractal curve. We have derived a formula which correlate the fracture energy with the fractal parameters of the fracture surfaces and analyzed some experimental data.
文摘We have theoretically analysed the perimeter-area relation and simulated its application to measuring the fractal dimension of fracture surfaces. It is proved that the fractal dimension D obtained by slit island method (SIM) is related to the dependence of measured area A(delta) of the slit island on yardstick delta. So in some cases, the dimension D obtained by SIM is dependent on yardstick and in other cases independent on yardstick delta. But in all cases, when delta-->0 the dimension D obtained by SIM approaches the real fractal dimension (similar dimension) of 'coastline' of the island. We analysed some experimental data and found some new and interesting characteristics of crack propagation in steels.
文摘Length-yardstick relation was used for measurement of the fractal dimension and the length of the initiator of Koch curves. It was found that the higher the fractal dimension and then the fracture toughness, the shorter the length of the initiator of the Koch curve for the crack lines would be.
文摘A simple parameterization of embedded atom method is proposed and two adjustable parameters are introduced to describe the pairwise potential and electron density. The embedded energy functions are obtained for fee metals Cu, Ag, Au, Ni, Pd and Pt through the standard fitting procedure of embedded atom method. To test the validity of the obtained functions, the formation energy of various defects are calculated.
文摘The present paper has studied the effects of dislocation density on the role of edge and screw dislocations and described further the parallel feature of the edge and screw dislocations and their role on the plastic deformation of metals.
文摘Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.
