Abstract: With the advent of the era of nanoelectronics,the unique electrical,optical and mechanical properties of carbon nanotubes as one-dimensional nanomaterials have attracted considerable interest and sparked discussion of their potential use in applications.Because of its good mechanical properties, carbon nanotubes can be used as the reinforcing materials with superior propertiesIn recent years,magnesium matrix composite of new high-strength lightweight composite materials developed rapidly.It has a high electrical and thermal conductivity, high specific strength and specific modulus, excellent damping properties, mechanical properties, high hardness and good wear resistance.In this paper, using the theory of continuum mechanics and ANSYS to solve carbon nanotubes reinforced magnesium matrix composite materials mechanics performance calculation.By using the finite element software ANSYS to contain crack defects of composite model, aims to study crack defects under the action of tensile load effect on the stress distribution of composite materials.The model without defects, magnesium matrix(vertical, transverse and circumferential defects) was selected respectively.Found in composite materials under tensile load, the vertical defects model is the most easy to fracture, and magnesium matrix contains circumferential defects is the most difficult to destroy.The model without defects is the most difficult to yield, while the magnesium matrix contains transverse defects is the easiest to yield, and the maximum yield stress appears at the junction of composite materials

Key words: With the advent of the era of nanoelectronics,the unique electrical,optical and mechanical properties of carbon nanotubes as one-dimensional nanomaterials have attracted considerable interest and sparked discussion of their potential use in applications.Because of its good mechanical properties, carbon nanotubes can be used as the reinforcing materials with superior propertiesIn recent years,magnesium matrix composite of new high-strength lightweight composite materials developed rapidly.It has a high electrical and thermal conductivity, high specific strength and specific modulus, excellent damping properties, mechanical properties, high hardness and good wear resistance.In this paper, using the theory of continuum mechanics and ANSYS to solve carbon nanotubes reinforced magnesium matrix composite materials mechanics performance calculation.By using the finite element software ANSYS to contain crack defects of composite model, aims to study crack defects under the action of tensile load effect on the stress distribution of composite materials.The model without defects, magnesium matrix(vertical, transverse and circumferential defects) was selected respectively.Found in composite materials under tensile load, the vertical defects model is the most easy to fracture, and magnesium matrix contains circumferential defects is the most difficult to destroy.The model without defects is the most difficult to yield, while the magnesium matrix contains transverse defects is the easiest to yield, and the maximum yield stress appears at the junction of composite materials