The Interaction Of Circular Cavity, Inclusion With Beeline Cracks By SH-wave

Using Green's Function method and the method of crack-division, the interaction problems of circular cavity, inclusion or a cylindrical canyon with cracks of any limited lengths near gap or inclusion by SH-wave are studied in this paper in the field of linearly elastic dynamic mechanics. Firstly a suitable Green's function, which is a fundamental solution of displacement field for an elastic space possessing circular cavity or inclusion while bearing out-of-plane harmonic line source force at any point, or for an elastic half space possessing a cylindrical canyon while bearing out-of-plane harmonic line source force at any point is constructed for the present problem. Then using the method of crack-division, integration for solution is established: while the scattering problems of SH-wave by gap or inclusion (include circular cavity ,inclusion or a cylindrical canyon) are studied, reverse stresses are inflicted along the cracks, that is, out-of-plane harmonic line source forces which are equal in the quantity but opposite in the direction to the stresses produced for the reason of SH-wave scattering by gap or inclusion are loaded at the region where cracks will appear, so cracks can be made out. So the expression of displacement and stress is established while gap(or inclusion)and cracks are existent. Using the expression dynamic stress concentration near the gap (or inclusion) and the variety of dynamic stress intensity factor at crack tip are discussed. The works in detail are as follows:1 .The Green's function is a fundamental solution of displacement field for anelastic space possessing circular cavity or inclusion while bearing out-of-plane. harmonic line source force at any point. Using one example crack-divisiontechnique is analyzed. The continuity, singularity and some other characteristicsof the Green's function are discussed.2.The problem of SH-wave scattering and dynamic stress concentration by circular cavity with cracks of any limited lengths near the gap is investigated. Using the Green's function which is suitable to the present problem, the expression of displacement and stress is established while the interaction of circular cavity with cracks is studied with crack-division technique. Dynamic stress concentration near the circular cavity is studied, and dynamic stress intensity factor at crack tip is discussed. Some examples and results are given. The influences of wave number, incident angles of SH-wave, and the geometrical location of the circular cavity and crack are discussed.3. The problem of SH-wave scattering and dynamic stress concentration bycircular inclusion with cracks of any limited lengths near the inclusion is investigated. Using the Green's function which is suitable to the present problem, the expression of displacement and stress is established while the interaction of circular inclusion with cracks is studied with crack-division technique. Dynamic stress concentration near the circular inclusion is studied, and dynamic stress intensity factor at crack tip is discussed. Some examples and results are given. The influences of wave number, incident angles of SH-wave, the geometrical location of the circular cavity and crack and the combination of different media parameters are discussed.4. The problem of SH-wave scattering and dynamic stress concentration by a cylindrical canyon with cracks of any limited lengths near the gap is investigated. Using the Green's function which is suitable to the present problem, the expression of displacement and stress is established while the interaction of the cylindrical canyon with cracks is studied with crack-division technique. Dynamic stress concentration near the cylindrical canyon is studied, and dynamic stress intensity factor at crack tip is discussed. Some examples and results are given. The influences of wave number, incident angles of SH-wave, and the geometrical location of the cylindrical canyon and crack are discussed.