In practical application, it is very important to master the influence of structure parameters on the mid-span deflection quantificationally. For large-span and heavy-duty gantry cranes, the influence of the rigid leg...In practical application, it is very important to master the influence of structure parameters on the mid-span deflection quantificationally. For large-span and heavy-duty gantry cranes, the influence of the rigid leg and the soft leg on mid-span deflection has not been considered in the past. In the paper, the mathematical model is established for universal large-span and heavy-duty gantry cranes. The analytical solution for the mid-span deflection of gantry-frame structure girder is derived and obtained based on the variation principle by considering the coupling effect of the bending moments of girder and legs, the axial force and the secondary bending moments. The relation between the load and the deflection on the mid-span of the gantry-frame structure girder is known. Then, the experimental model is designed according to dimensional analysis method. And experiments were performed on the WEW-600 B type testing machine. Hackling experimental data, the regular of the load and deflection on the girder mid-span is obtained, namely, the deformation of the gantry-frame structure resists the external load to do work. The validity of the nonlinear analytical solution of the girder deflection is verified. Experimental results show that the analytical solution of the gantry-frame structure deflection has much higher calculation accuracy than previous calculation method. This work provides a theoretical basis for the design and inspection of gantry-frame structures.展开更多
Evaluation of Gamma Index Analysis for Detecting Errors in Patient-specific Quality Assurance in Intensity Modulated Radiotherapy Taylan Tugrul1(1.Department of Radiation Oncology,Medicine Faculty of Van Yüzü...Evaluation of Gamma Index Analysis for Detecting Errors in Patient-specific Quality Assurance in Intensity Modulated Radiotherapy Taylan Tugrul1(1.Department of Radiation Oncology,Medicine Faculty of Van YüzüncüYıl University,Van,Turkey)Abstract:Quality assurance practices performed before treatment are believed to identify various potential errors.In this study,2-dimensional(2D)dosimetric results were analyzed by making some intentional mistakes in six different treatment plans.In this way,the detectability of errors was investigated.In all segments of all treatment plans,one of the multileaf collimators was kept fixed at different positions on the central axis.In addition to multileaf collimators error,gantry error was also examined in the study.The dose distribution results obtained by Treatment Planning System(TPS)were compared with those obtained by the 2D array device,both as local calculation and global calculation methods,using the gamma analysis method.When the results are examined in the case where the Multi-leaf collimators(MLC)is fixed at the 1 cm position.展开更多
基金Project(51175442)supported by the National Natural Science Foundation of ChinaProject(QD2012A09)supported by Teachers’College Research Project,ChinaProject(14ZA0263)supported by Research Project of Sichuan Provincial Department of Education,China
文摘In practical application, it is very important to master the influence of structure parameters on the mid-span deflection quantificationally. For large-span and heavy-duty gantry cranes, the influence of the rigid leg and the soft leg on mid-span deflection has not been considered in the past. In the paper, the mathematical model is established for universal large-span and heavy-duty gantry cranes. The analytical solution for the mid-span deflection of gantry-frame structure girder is derived and obtained based on the variation principle by considering the coupling effect of the bending moments of girder and legs, the axial force and the secondary bending moments. The relation between the load and the deflection on the mid-span of the gantry-frame structure girder is known. Then, the experimental model is designed according to dimensional analysis method. And experiments were performed on the WEW-600 B type testing machine. Hackling experimental data, the regular of the load and deflection on the girder mid-span is obtained, namely, the deformation of the gantry-frame structure resists the external load to do work. The validity of the nonlinear analytical solution of the girder deflection is verified. Experimental results show that the analytical solution of the gantry-frame structure deflection has much higher calculation accuracy than previous calculation method. This work provides a theoretical basis for the design and inspection of gantry-frame structures.
文摘Evaluation of Gamma Index Analysis for Detecting Errors in Patient-specific Quality Assurance in Intensity Modulated Radiotherapy Taylan Tugrul1(1.Department of Radiation Oncology,Medicine Faculty of Van YüzüncüYıl University,Van,Turkey)Abstract:Quality assurance practices performed before treatment are believed to identify various potential errors.In this study,2-dimensional(2D)dosimetric results were analyzed by making some intentional mistakes in six different treatment plans.In this way,the detectability of errors was investigated.In all segments of all treatment plans,one of the multileaf collimators was kept fixed at different positions on the central axis.In addition to multileaf collimators error,gantry error was also examined in the study.The dose distribution results obtained by Treatment Planning System(TPS)were compared with those obtained by the 2D array device,both as local calculation and global calculation methods,using the gamma analysis method.When the results are examined in the case where the Multi-leaf collimators(MLC)is fixed at the 1 cm position.
