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Stress distribution near sharp orthotropic bi-material notch tips
Krepl, Ondřej ; Klusák, Jan (referee) ; Hrstka, Miroslav (advisor)
Presented diploma thesis is concerned with problems of a stress singularity exponent and a generalized stress intensity factor determination, by dint the stress field in the vicinity of the stress concentrator can be consecutively determined. This task is possible to sectionalize into three parts. The first part summarizes basic information about linear anisotropic materials, deals with fundamentals of the linear elastic fracture mechanics and introduces its generalization to the case of the generalized stress intensity factors. The second part is dedicated to a special theory of anisotropic elasticity - Lekhnitskii-Eshelby-Stroh formalism (LES). Furthermore, a theory of the psi-integral is introduced, by dint the stress intensity factor is determined. The final part applies the LES theory and the psi-integral to the concrete material configuration of a crack on the bimaterial interface, a special example of a sharp bimaterial notch. By means of analytical-numerical algorithm in ANSYS and Silverforst FNT95 software the stress singularity exponents and generalised stress intensity factors are consecutively computed.
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A study of the stress distribution around the bimaterial notch tip
Hrstka, Miroslav ; Klusák, Jan (referee) ; Profant, Tomáš (advisor)
Presented bachelor’s thesis deals with determination of stress singularity exponent, by which is possible to completely define the stress distribution around the bimaterial notch tip. This task is divided in four parts. The first part concerns with basics of fracture mechanics, concretely linear elastic fracture mechanics of crack and Irwin’s conception of stress intensity factor. The second part deals with generalizing of linear fracture mechanics to notches. In the third part is initiated the numeric-analytical algorithm for computation of stress singularity exponent and determination of strains and stresses of given notch, which is compounded from two orthotropic materials. The last part is created by numerical example, in which the concrete configurations of notches are tested in calculating software.
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A study of the stress distribution around the bimaterial notch tip in the terms of the generalized stress intensity factor
Hrstka, Miroslav ; Kotoul, Michal (referee) ; Profant, Tomáš (advisor)
The presented diploma thesis deals with a problem of a generalized stress intensity factor determination and a consecutive study of stress distribution around the bimaterial notch tip, combining analytical and numerical methods. This task is possible to sectionalize into three parts. The first part is dedicated to the fundamentals of the linear fracture mechanics and the mechanics of composite materials. The second part deals with methods of anisotropic plane elasticity solution. Pursuant to the solution the computational models in the third part are created. The first model makes for determination of a singularity exponent eigenvalue by dint of Lekhnitskii-Eshelby-Stroh formalism. The second model makes for determination of the generalized stress intensity factor using psi-integral method, which is based on the Betti reciprocal theorem. All needed calculation are performed in the software ANSYS 12, Maple 12 and Silverforst FTN95. Results will be compared with the values obtained from a direct method of the generalised stress intensity factor determination.
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Stress distribution near sharp orthotropic bi-material notch tips
Krepl, Ondřej ; Klusák, Jan (referee) ; Hrstka, Miroslav (advisor)
Presented diploma thesis is concerned with problems of a stress singularity exponent and a generalized stress intensity factor determination, by dint the stress field in the vicinity of the stress concentrator can be consecutively determined. This task is possible to sectionalize into three parts. The first part summarizes basic information about linear anisotropic materials, deals with fundamentals of the linear elastic fracture mechanics and introduces its generalization to the case of the generalized stress intensity factors. The second part is dedicated to a special theory of anisotropic elasticity - Lekhnitskii-Eshelby-Stroh formalism (LES). Furthermore, a theory of the psi-integral is introduced, by dint the stress intensity factor is determined. The final part applies the LES theory and the psi-integral to the concrete material configuration of a crack on the bimaterial interface, a special example of a sharp bimaterial notch. By means of analytical-numerical algorithm in ANSYS and Silverforst FNT95 software the stress singularity exponents and generalised stress intensity factors are consecutively computed.
|
|
|
A study of the stress distribution around the bimaterial notch tip in the terms of the generalized stress intensity factor
Hrstka, Miroslav ; Kotoul, Michal (referee) ; Profant, Tomáš (advisor)
The presented diploma thesis deals with a problem of a generalized stress intensity factor determination and a consecutive study of stress distribution around the bimaterial notch tip, combining analytical and numerical methods. This task is possible to sectionalize into three parts. The first part is dedicated to the fundamentals of the linear fracture mechanics and the mechanics of composite materials. The second part deals with methods of anisotropic plane elasticity solution. Pursuant to the solution the computational models in the third part are created. The first model makes for determination of a singularity exponent eigenvalue by dint of Lekhnitskii-Eshelby-Stroh formalism. The second model makes for determination of the generalized stress intensity factor using psi-integral method, which is based on the Betti reciprocal theorem. All needed calculation are performed in the software ANSYS 12, Maple 12 and Silverforst FTN95. Results will be compared with the values obtained from a direct method of the generalised stress intensity factor determination.
|
|
|
A study of the stress distribution around the bimaterial notch tip
Hrstka, Miroslav ; Klusák, Jan (referee) ; Profant, Tomáš (advisor)
Presented bachelor’s thesis deals with determination of stress singularity exponent, by which is possible to completely define the stress distribution around the bimaterial notch tip. This task is divided in four parts. The first part concerns with basics of fracture mechanics, concretely linear elastic fracture mechanics of crack and Irwin’s conception of stress intensity factor. The second part deals with generalizing of linear fracture mechanics to notches. In the third part is initiated the numeric-analytical algorithm for computation of stress singularity exponent and determination of strains and stresses of given notch, which is compounded from two orthotropic materials. The last part is created by numerical example, in which the concrete configurations of notches are tested in calculating software.
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