OSFAC for Windows是运行在Windows系统下的海洋平台结构疲劳分析与计算软件系统,可以用于导管架平台构件的常规疲劳分析、疲劳裂纹扩展分析、疲劳可靠性分析、疲劳强度校核、含缺陷平台构件断裂评估及其断裂安全可靠性评估等。介绍该...OSFAC for Windows是运行在Windows系统下的海洋平台结构疲劳分析与计算软件系统,可以用于导管架平台构件的常规疲劳分析、疲劳裂纹扩展分析、疲劳可靠性分析、疲劳强度校核、含缺陷平台构件断裂评估及其断裂安全可靠性评估等。介绍该软件系统的各模块组成、计算流程、主要功能、安装与运行,并与SACS和FACTS等国外相关软件作了比较。展开更多
Structural integrity procedures were used to demonstrate the fitness for the purpose of engineering components transmitting loads. The prediction of the fracture strength of titanium alloys containing sharp notches th...Structural integrity procedures were used to demonstrate the fitness for the purpose of engineering components transmitting loads. The prediction of the fracture strength of titanium alloys containing sharp notches through the damage model depends on the un-notched strength and the critical length of the damage zone ahead of the notch. In general, the critical length of the damage zone depends on the material, specimen, and size of the sharp notch. Modifications were made in one of the stress fracture criteria known as the average stress criterion for accurate prediction of notched tensile strength of titanium alloy specimen containing sharp notches. To examine the adequacy of these modifications, fracture data of center-cracked titanium alloys with various thicknesses are considered. The notched （fracture） strength estimates are found to be close to the test results. The modified average stress criterion is very simple to predict the notched tensile strength.展开更多
The defect assessment in butt-welded joint of ASTM A36 steel plates and 7075-T7351 aluminum alloy plates containing transverse through thickness crack was analyzed using SINTAP procedure and FEA incorporating weld ind...The defect assessment in butt-welded joint of ASTM A36 steel plates and 7075-T7351 aluminum alloy plates containing transverse through thickness crack was analyzed using SINTAP procedure and FEA incorporating weld induced residual stresses. Weld induced longitudinal residual stress profile can be obtained through SINTAP procedure, FEA or experimental analysis. This residual stress profile can be fitted with the trapezoidal residual stress profile available in SINTAP. For three different cases, crack length and residual stress intensity factor （SIF） are calculated and its comparison with the results obtained through FEA is plotted with respect to crack length. The stress intensity factor for mechanical loading is also plotted in the same graph. Using this graphical plot, the total SIF, including residual stress and mechanical loading, can be calculated for any particular crack size. The total SIF can be compared with the fracture toughness of the material for damage tolerance analysis. Also a failure assessment diagram is drawn for welded 7075-T7351 aluminum alloy plates with different crack sizes for as-welded （only residual stress） and mechanical loading along with the existing weld induced residual stresses to show the safety level for a particular crack size and mechanical loading.展开更多
Fracture data of both parent metal and weldment metals from surface cracked tensile plates made of 2219-T87 Al alloy at cryogenic temperatures were correlated using a modified inherent flaw model. Fracture parameters ...Fracture data of both parent metal and weldment metals from surface cracked tensile plates made of 2219-T87 Al alloy at cryogenic temperatures were correlated using a modified inherent flaw model. Fracture parameters to generate the failure assessment diagram were determined for the material. Fracture analysis was carried out considering the ultimate tensile strength value and the fracture data of aluminium base metal and weldment metal generated from center–surface cracked tensile specimens having different thicknesses. The failure assessment diagram of a material generated from tensile fracture plate configuration can be applied to failure pressure estimation of any cracked component, made of the same material.展开更多
Active velocity tomography was used to determine the stress state and rock burst hazards in a deep coal mine. The deepest longwall face, number 3207 in the Xingcun colliery, was the location of the field trials. The p...Active velocity tomography was used to determine the stress state and rock burst hazards in a deep coal mine. The deepest longwall face, number 3207 in the Xingcun colliery, was the location of the field trials. The positive correlation between stress and seismic velocity was used to link the velocity data with stratum stresses. A GeoPen SE2404NT data acquisition system was used to collect seismic data from 300 g explosive charges fired by instantaneous electric detonator and located in the tail entry. The geophones were installed on the rock bolts in the head entry of LW3207. Velocity inversion shows an inhomogeneous distribution of stress in the longvvall face that could not be obtained from theory or numerical simulations. Three abnormally high P-wave velocity regions were identified that were located on the corners of the two roadways and at the face end near the rail entry side. The maximum velocity gradient is located at the open cut off near the rail entry and is the area most dangerous for rock burst. Mining-induced tremors recorded by a micro-seismic monitoring system demonstrated that the position of energy release during mining coincides with the high velocity gradient area. This technology aids technicians in the coal mine as they design measures to weaken or eliminate potential danger during subsequent mining.展开更多
The nearly EW-trending East Kunlun fault zone is the north boundary of the Bayan Har block.The activity characteristics and the position of the eastern end of its eastward extension are of great significance to probin...The nearly EW-trending East Kunlun fault zone is the north boundary of the Bayan Har block.The activity characteristics and the position of the eastern end of its eastward extension are of great significance to probing into the dynamic mechanism of formation of the east edge of the Tibetan Plateau,and also lay the foundation for seismic risk assessment of the fault zone.The following results are obtained by analysis based on satellite image interpretation of landforms,surface rupture survey,terrace scarp deformation survey,and terrace dating data on the eastern part of the East Kunlun fault zone:(1)the Luocha segment is a Holocene active fault,where a reverse L-shape paleoearthquake surface rupture zone of about 50 km long is located;(2)the Luocha segment is characterized by left-lateral slip movement under the compression-shear condition since the later period of the Late Pleistocene,with a rate of 7.68–9.37 mm/a and a vertical slip rate of 0.7–0.9 mm/a,which are basically in accord with the activity rate of segments on its west side.The results indicate that it is a part of eastward extension of the East Kunlun fault zone;(3)the high-speed linear horizontal slip of the nearly EW-trending East Kunlun fault zone is blocked by the South China block at east,and transforms into the vertical movement of the nearly SN-NNE trending Minjiang fault zone and the Longmenshan fault zone,and the uplift of Longmenshan and Minjiang.The area where transform of the two tectonic systems occurred confines the position of the east end;(4)Luocha segment and Maqu segment constitute the"Maqu seismic gap",so,seismic risk at Maqu segment is higher than that at Luocha segment,which should attract more attention.展开更多
文摘OSFAC for Windows是运行在Windows系统下的海洋平台结构疲劳分析与计算软件系统,可以用于导管架平台构件的常规疲劳分析、疲劳裂纹扩展分析、疲劳可靠性分析、疲劳强度校核、含缺陷平台构件断裂评估及其断裂安全可靠性评估等。介绍该软件系统的各模块组成、计算流程、主要功能、安装与运行,并与SACS和FACTS等国外相关软件作了比较。
文摘Structural integrity procedures were used to demonstrate the fitness for the purpose of engineering components transmitting loads. The prediction of the fracture strength of titanium alloys containing sharp notches through the damage model depends on the un-notched strength and the critical length of the damage zone ahead of the notch. In general, the critical length of the damage zone depends on the material, specimen, and size of the sharp notch. Modifications were made in one of the stress fracture criteria known as the average stress criterion for accurate prediction of notched tensile strength of titanium alloy specimen containing sharp notches. To examine the adequacy of these modifications, fracture data of center-cracked titanium alloys with various thicknesses are considered. The notched （fracture） strength estimates are found to be close to the test results. The modified average stress criterion is very simple to predict the notched tensile strength.
文摘The defect assessment in butt-welded joint of ASTM A36 steel plates and 7075-T7351 aluminum alloy plates containing transverse through thickness crack was analyzed using SINTAP procedure and FEA incorporating weld induced residual stresses. Weld induced longitudinal residual stress profile can be obtained through SINTAP procedure, FEA or experimental analysis. This residual stress profile can be fitted with the trapezoidal residual stress profile available in SINTAP. For three different cases, crack length and residual stress intensity factor （SIF） are calculated and its comparison with the results obtained through FEA is plotted with respect to crack length. The stress intensity factor for mechanical loading is also plotted in the same graph. Using this graphical plot, the total SIF, including residual stress and mechanical loading, can be calculated for any particular crack size. The total SIF can be compared with the fracture toughness of the material for damage tolerance analysis. Also a failure assessment diagram is drawn for welded 7075-T7351 aluminum alloy plates with different crack sizes for as-welded （only residual stress） and mechanical loading along with the existing weld induced residual stresses to show the safety level for a particular crack size and mechanical loading.
文摘Fracture data of both parent metal and weldment metals from surface cracked tensile plates made of 2219-T87 Al alloy at cryogenic temperatures were correlated using a modified inherent flaw model. Fracture parameters to generate the failure assessment diagram were determined for the material. Fracture analysis was carried out considering the ultimate tensile strength value and the fracture data of aluminium base metal and weldment metal generated from center–surface cracked tensile specimens having different thicknesses. The failure assessment diagram of a material generated from tensile fracture plate configuration can be applied to failure pressure estimation of any cracked component, made of the same material.
基金support for this work was provided by the National Basic Research Program of China (No. 2010CB226805)the National Natural Science Foundation of China (Nos. 50474068 and50490273)+1 种基金the Independent Foundation of State Key Laboratory of Coal Resources and Mine Safety (No. SKLCRSM10X05)the Open Foundation of State Key Laboratory of Coal Resources and Mine Safety (No. 10KF05)
文摘Active velocity tomography was used to determine the stress state and rock burst hazards in a deep coal mine. The deepest longwall face, number 3207 in the Xingcun colliery, was the location of the field trials. The positive correlation between stress and seismic velocity was used to link the velocity data with stratum stresses. A GeoPen SE2404NT data acquisition system was used to collect seismic data from 300 g explosive charges fired by instantaneous electric detonator and located in the tail entry. The geophones were installed on the rock bolts in the head entry of LW3207. Velocity inversion shows an inhomogeneous distribution of stress in the longvvall face that could not be obtained from theory or numerical simulations. Three abnormally high P-wave velocity regions were identified that were located on the corners of the two roadways and at the face end near the rail entry side. The maximum velocity gradient is located at the open cut off near the rail entry and is the area most dangerous for rock burst. Mining-induced tremors recorded by a micro-seismic monitoring system demonstrated that the position of energy release during mining coincides with the high velocity gradient area. This technology aids technicians in the coal mine as they design measures to weaken or eliminate potential danger during subsequent mining.
基金supported by the Systematic Scientific Investigation of Yushu Earthquake(Grant No.02106601)National Key Basic Research Program of China(Grant No.2008CB42570)Basic Research Fund of Institute of Earthquake Science(Grant No.02092437)
文摘The nearly EW-trending East Kunlun fault zone is the north boundary of the Bayan Har block.The activity characteristics and the position of the eastern end of its eastward extension are of great significance to probing into the dynamic mechanism of formation of the east edge of the Tibetan Plateau,and also lay the foundation for seismic risk assessment of the fault zone.The following results are obtained by analysis based on satellite image interpretation of landforms,surface rupture survey,terrace scarp deformation survey,and terrace dating data on the eastern part of the East Kunlun fault zone:(1)the Luocha segment is a Holocene active fault,where a reverse L-shape paleoearthquake surface rupture zone of about 50 km long is located;(2)the Luocha segment is characterized by left-lateral slip movement under the compression-shear condition since the later period of the Late Pleistocene,with a rate of 7.68–9.37 mm/a and a vertical slip rate of 0.7–0.9 mm/a,which are basically in accord with the activity rate of segments on its west side.The results indicate that it is a part of eastward extension of the East Kunlun fault zone;(3)the high-speed linear horizontal slip of the nearly EW-trending East Kunlun fault zone is blocked by the South China block at east,and transforms into the vertical movement of the nearly SN-NNE trending Minjiang fault zone and the Longmenshan fault zone,and the uplift of Longmenshan and Minjiang.The area where transform of the two tectonic systems occurred confines the position of the east end;(4)Luocha segment and Maqu segment constitute the"Maqu seismic gap",so,seismic risk at Maqu segment is higher than that at Luocha segment,which should attract more attention.
