The displacement fields u_x,u_y at growing crack tip of LYI2-M specimens with double edge cracks are measured using moire method.The experimental singularity fields are compared with GH theoretical field [12-14].The s...The displacement fields u_x,u_y at growing crack tip of LYI2-M specimens with double edge cracks are measured using moire method.The experimental singularity fields are compared with GH theoretical field [12-14].The size and shape of the experimental GH singularity fields are obtained.The error in both the experimental and theoretical evaluations is controlled within ±10%.The experiments show that there is (In A/r)^(+1)singularity dominant around a growing crack tip.The shape of this dominant region ranges from butterfly wing to oblate and circular.Inside GH-field,there is a 3-D deformed damage zone where no GH sin- gularity exists.展开更多
By expanding the yielding function according toTaylor series and neglecting the high order terms, the elastoplastic constitutive equation is written in a linear complementary form. Based on this linear complementary f...By expanding the yielding function according toTaylor series and neglecting the high order terms, the elastoplastic constitutive equation is written in a linear complementary form. Based on this linear complementary form and the principle of virtual work, a finite element-complementary method is derived for elastoplastic problem. This method is available for materials which satisfy either associated or nonassociated flow rule. In addition, the existence and uniqueness oj solution for the method are also discussed and some useful conclusions are given.展开更多
The behavior of supercavitating and cavitatlng flow around a conical body of revolution with and without ventilation at several angles of attack was studied experimentally. The hydrodynamic forces for a range of cavit...The behavior of supercavitating and cavitatlng flow around a conical body of revolution with and without ventilation at several angles of attack was studied experimentally. The hydrodynamic forces for a range of cavitation number were measured. Comparisons of the appearance and the hydrodynamic forces in condition of cavity with and without ventilation were made over the same range of the cavitation number, and a well agreement was obtained. The changes of the drag were especially studied. The experimental results showed that the drag of the model decreased with the presence of supercavity under the ventilation condition.展开更多
基金The project suppoted by National Natural Science Foundation of China
文摘The displacement fields u_x,u_y at growing crack tip of LYI2-M specimens with double edge cracks are measured using moire method.The experimental singularity fields are compared with GH theoretical field [12-14].The size and shape of the experimental GH singularity fields are obtained.The error in both the experimental and theoretical evaluations is controlled within ±10%.The experiments show that there is (In A/r)^(+1)singularity dominant around a growing crack tip.The shape of this dominant region ranges from butterfly wing to oblate and circular.Inside GH-field,there is a 3-D deformed damage zone where no GH sin- gularity exists.
文摘By expanding the yielding function according toTaylor series and neglecting the high order terms, the elastoplastic constitutive equation is written in a linear complementary form. Based on this linear complementary form and the principle of virtual work, a finite element-complementary method is derived for elastoplastic problem. This method is available for materials which satisfy either associated or nonassociated flow rule. In addition, the existence and uniqueness oj solution for the method are also discussed and some useful conclusions are given.
文摘The behavior of supercavitating and cavitatlng flow around a conical body of revolution with and without ventilation at several angles of attack was studied experimentally. The hydrodynamic forces for a range of cavitation number were measured. Comparisons of the appearance and the hydrodynamic forces in condition of cavity with and without ventilation were made over the same range of the cavitation number, and a well agreement was obtained. The changes of the drag were especially studied. The experimental results showed that the drag of the model decreased with the presence of supercavity under the ventilation condition.
