Based on the deficiency of the traditional total least squares method（TLS） in the field of geodetic inversion, the mixed error characteristics of the errors in variables（EIV） model were analyzed by considering the...Based on the deficiency of the traditional total least squares method（TLS） in the field of geodetic inversion, the mixed error characteristics of the errors in variables（EIV） model were analyzed by considering the distance azimuth measurement error in strain inversion from distance changes, which resulted in the improved mixed total least squares method（IMTLS） with generalized mixed EIV model. Finally, three comparison schemes of strain inversion from distance changes using measured data were implemented to test the proposed method. The results showed that the IMTLS method outperformed the traditional least squares（LS） and TLS methods in parameters estimation, accuracy evaluation, actual EIV model characteristics, and five strain eigenvalues.展开更多
In this paper a new method for preventing welding hot cracking—the inverse strain method(ISM)is developed on the principle of welding mechan- ics.Effectiveness and feasiblity of method in preventing welding hot crack...In this paper a new method for preventing welding hot cracking—the inverse strain method(ISM)is developed on the principle of welding mechan- ics.Effectiveness and feasiblity of method in preventing welding hot cracking of high strength aluminum alloy LY12CZ by synchronous rolling during welding (SRDW)along both sides of the weld at a suitable distance behind the welding arc are examined.Experimental resulte indicate that welding hot cracking of LY12CY can be effectively prevented and the mechanical properties of welded joint can also be improved by the method.It is an important new solution for preventing hot cracking in welding of sheet metal.展开更多
基金supported by both the National Natural Science Foundation of China (41204011)the fundamental research funds for the Central Universities (2014QNB17)
文摘Based on the deficiency of the traditional total least squares method（TLS） in the field of geodetic inversion, the mixed error characteristics of the errors in variables（EIV） model were analyzed by considering the distance azimuth measurement error in strain inversion from distance changes, which resulted in the improved mixed total least squares method（IMTLS） with generalized mixed EIV model. Finally, three comparison schemes of strain inversion from distance changes using measured data were implemented to test the proposed method. The results showed that the IMTLS method outperformed the traditional least squares（LS） and TLS methods in parameters estimation, accuracy evaluation, actual EIV model characteristics, and five strain eigenvalues.
文摘In this paper a new method for preventing welding hot cracking—the inverse strain method(ISM)is developed on the principle of welding mechan- ics.Effectiveness and feasiblity of method in preventing welding hot cracking of high strength aluminum alloy LY12CZ by synchronous rolling during welding (SRDW)along both sides of the weld at a suitable distance behind the welding arc are examined.Experimental resulte indicate that welding hot cracking of LY12CY can be effectively prevented and the mechanical properties of welded joint can also be improved by the method.It is an important new solution for preventing hot cracking in welding of sheet metal.
