VAT(Variable Angle Tow Placement)是当前国际先进的计算机控制纤维预制体成型工艺。本文对VAT工艺中的三种多发性制品缺陷及缺陷程度进行试验设计,并采用VARI工艺制备10种CFRP板制件。运用超声相控阵C扫描、SEM进行宏观检测和细观表...VAT(Variable Angle Tow Placement)是当前国际先进的计算机控制纤维预制体成型工艺。本文对VAT工艺中的三种多发性制品缺陷及缺陷程度进行试验设计,并采用VARI工艺制备10种CFRP板制件。运用超声相控阵C扫描、SEM进行宏观检测和细观表征。对CFRP制件进行纵向拉伸与压缩试验,研究了变角度牵引铺缝对CFRP板材力学性能的影响,对进一步完善VAT工艺,以及质量体系建立和效益提升十分有益。展开更多
Hydraulic fracturing,as a key technology of deep energy exploitation,accelerates the rapid development of the modern petroleum industry.To study the mechanisms of hydraulic fracture propagation and rock failure mode o...Hydraulic fracturing,as a key technology of deep energy exploitation,accelerates the rapid development of the modern petroleum industry.To study the mechanisms of hydraulic fracture propagation and rock failure mode of the vertical well hydraulic fracturing,the true triaxial hydraulic fracturing test and numerical simulation are carried out,and the influence of the principal stress difference,water injection displacement,perforation angle and natural fracture on fracture propagation is analyzed.The results show that the fracture propagation mode of limestone is mainly divided into two types:the single vertical fracture and the transverse-longitudinal crossed complex fracture.Under high displacement,the fracturing pressure is larger,and the secondary fracture is more likely to occur,while variable displacement loading is more likely to induce fracture network.Meanwhile,the amplitude of acoustic emission(AE)waveform of limestone during fracturing is between 0.01 and 0.02 mV,and the main frequency is maintained in the range of 230−300 kHz.When perforation angleθ=45°,it is easy to produce the T-type fracture that connects with the natural fracture,while X-type cracks are generated whenθ=30°.The results can be used as a reference for further study on the mechanism of limestone hydraulic fracturing.展开更多
文摘VAT(Variable Angle Tow Placement)是当前国际先进的计算机控制纤维预制体成型工艺。本文对VAT工艺中的三种多发性制品缺陷及缺陷程度进行试验设计,并采用VARI工艺制备10种CFRP板制件。运用超声相控阵C扫描、SEM进行宏观检测和细观表征。对CFRP制件进行纵向拉伸与压缩试验,研究了变角度牵引铺缝对CFRP板材力学性能的影响,对进一步完善VAT工艺,以及质量体系建立和效益提升十分有益。
基金Projects(51879148,51709159,51911530214)supported by the National Natural Science Foundation of ChinaProject(2019GSF111030)supported by Shandong Provincial Key R&D Program of ChinaProject(KT201804)supported by the Project of Special Fund for Science and Technology of Water Resources Department of Guizhou Province,China。
文摘Hydraulic fracturing,as a key technology of deep energy exploitation,accelerates the rapid development of the modern petroleum industry.To study the mechanisms of hydraulic fracture propagation and rock failure mode of the vertical well hydraulic fracturing,the true triaxial hydraulic fracturing test and numerical simulation are carried out,and the influence of the principal stress difference,water injection displacement,perforation angle and natural fracture on fracture propagation is analyzed.The results show that the fracture propagation mode of limestone is mainly divided into two types:the single vertical fracture and the transverse-longitudinal crossed complex fracture.Under high displacement,the fracturing pressure is larger,and the secondary fracture is more likely to occur,while variable displacement loading is more likely to induce fracture network.Meanwhile,the amplitude of acoustic emission(AE)waveform of limestone during fracturing is between 0.01 and 0.02 mV,and the main frequency is maintained in the range of 230−300 kHz.When perforation angleθ=45°,it is easy to produce the T-type fracture that connects with the natural fracture,while X-type cracks are generated whenθ=30°.The results can be used as a reference for further study on the mechanism of limestone hydraulic fracturing.
