The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile p...The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile preform as the solution of lightweight reinforcement in various applications. Investigation into the development of 3D thin shells has led to different manufacturing processes. However, 3D thin shell preforms are mostly made by weaving and knitting, but nonwoven, winding, and/or layup techniques have been reported for over a decade. Owing to the complex thin shell manufacturing processes, they are not similar to the conventional methods. The different 3D thin shell preforms can extend the opportunities for new applications in various technical fields. This study presents existing research gaps and a few potential issues to be solved regarding 3D thin shell preforms in the near future.展开更多
The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile p...The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile preform as the solution of lightweight reinforcement in various applications. Investigation into the development of 3D thin shells has led to different manufacturing processes. However, 3D thin shell preforms are mostly made by weaving and knitting, but nonwoven, winding, and/or layup techniques have been reported for over a decade. Owing to the complex thin shell manufacturing processes, they are not similar to the conventional methods. The different 3D thin shell preforms can extend the opportunities for new applications in various technical fields. This study presents existing research gaps and a few potential issues to be solved regarding 3D thin shell preforms in the near future.展开更多
The manufacturing of three-dimensional textile preforms used for composites started to re-ceive much attention in the last decade.The major barriers to accelerating the transition from thelamination of two-dimensional...The manufacturing of three-dimensional textile preforms used for composites started to re-ceive much attention in the last decade.The major barriers to accelerating the transition from thelamination of two-dimensional fabrics to manufacturing integral three-dimensional near-netshaped textile preforms are high cost and database deficiency.To reduce the cost of weaving three-dimensional preforms,and make full use of the potential of conventional looms,a rig was designedwhich can convert two-dimensional woven fabric to particular three-dimensional preforms wherethe yarn is orientated in the directions of maximum stress.展开更多
Three-dimensional(3 D)braided composites are a kind of advanced ones and are used in the aeronautical and astronautical fields more widely.The advantages,usages,shortages and disadvantages of 3D braided composites are...Three-dimensional(3 D)braided composites are a kind of advanced ones and are used in the aeronautical and astronautical fields more widely.The advantages,usages,shortages and disadvantages of 3D braided composites are analyzed,and the possible approach of improving the properties of the materials is presented,that is,a new type of 3D full 5-directional braided composites is developed.The methods of making this type of preform are proposed.It is pointed out that the four-step braiding which is the most possible to realize industrialized production almost has no effect on the composites'properties.By analyzing the simulation model,the advantages of the material compared with the 3D 4-directional and 5-directional materials are presented.Finally,a microstructural model is analyzed to lay the foundation for the future theoretical analysis of these composites.展开更多
The mechanical properties of silica material in the monolithic form are ;far from acceptable levels. In this paper, 3D stitched quartz preform was used for the fiber reinforcement, and quartz fibers- reinforced silica...The mechanical properties of silica material in the monolithic form are ;far from acceptable levels. In this paper, 3D stitched quartz preform was used for the fiber reinforcement, and quartz fibers- reinforced silica composites were prepared by the silica sol-infiltration-sintering method. The density of the composite was up to 1.71 g/cm3 after 10 infiltration-sintering cycles. The flexural strength and the in-plane shear strength were 61.7 MPa and 20.3 MPa, respectively. The flexural stress-deflection curve exhibited mostly nonlinear behavior, which was different from that of monolithic ceramics. Because of the existence of the fiber in Z axis direction, shearing property between the different layers of 3D stitched composites were greatly enhanced. Toughness effect of the 3D stitched quartz preform was conspicuous. The as-fabricated composites showed non-catastronhic failure behavior resulting from weak fiber/matrix interface.展开更多
目的:评价3D打印模型及三维预成型钛网在复杂上颌骨骨折治疗中的临床应用效果。方法:回顾性分析2017年1月—2018年10月在绍兴市中心医院口腔颌面外科治疗的6例复杂上颌骨骨折患者,头颅数据通过16层CT扫描,导入计算机辅助设计Mimics 10.0...目的:评价3D打印模型及三维预成型钛网在复杂上颌骨骨折治疗中的临床应用效果。方法:回顾性分析2017年1月—2018年10月在绍兴市中心医院口腔颌面外科治疗的6例复杂上颌骨骨折患者,头颅数据通过16层CT扫描,导入计算机辅助设计Mimics 10.01软件和Geomagic Studio 2013软件,精确分割骨折处并重建三维模型,在软件中模拟骨折复位,将骨折复位前、后的数据通过3D打印技术打印l∶l比例大小的骨折模型。术前根据实体模型完成钛网的预弯制,术后对手术效果进行评价。结果:6例患者均顺利完成手术,平均随访12个月,患者对面部轮廓及咬合关系恢复满意5例,比较满意1例。结论:对于复杂上颌骨骨折患者,3D打印模型及三维预成型钛网的使用有助于缩短手术时间,降低术后不良事件发生率,提高骨折复位效果及面部的对称性。展开更多
Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the f...Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.展开更多
With the increasing demand of light structure composite in industry, carbon and glass fibres are more and more used, because of their light mass, high strength, high temperature endurance and erosion resistance. This ...With the increasing demand of light structure composite in industry, carbon and glass fibres are more and more used, because of their light mass, high strength, high temperature endurance and erosion resistance. This paper focuses on the process of forming a preform. Up to the finished preform, the multilayer reinforced fabrics are subjected to the following procedures: pattern design, cutting and sewing. Considering the fabric properties, the 3-dimensional CAD software and sewing machines, which are generally used in the clothing industry, are also suitable for the processing of the reinforced fabrics. This study aims also to the changes of property arising from the sewing process. Bending stiffness and changes of thickness after sewing are studied. These properties will provide input data for CAD pattern design.展开更多
文摘The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile preform as the solution of lightweight reinforcement in various applications. Investigation into the development of 3D thin shells has led to different manufacturing processes. However, 3D thin shell preforms are mostly made by weaving and knitting, but nonwoven, winding, and/or layup techniques have been reported for over a decade. Owing to the complex thin shell manufacturing processes, they are not similar to the conventional methods. The different 3D thin shell preforms can extend the opportunities for new applications in various technical fields. This study presents existing research gaps and a few potential issues to be solved regarding 3D thin shell preforms in the near future.
文摘The automobiles, aircraft, and lightweight industries continuously demand thin near-net-shape preforms just out-of-machine as close to the final shape. This study addresses the possibilities of 3D thin shell textile preform as the solution of lightweight reinforcement in various applications. Investigation into the development of 3D thin shells has led to different manufacturing processes. However, 3D thin shell preforms are mostly made by weaving and knitting, but nonwoven, winding, and/or layup techniques have been reported for over a decade. Owing to the complex thin shell manufacturing processes, they are not similar to the conventional methods. The different 3D thin shell preforms can extend the opportunities for new applications in various technical fields. This study presents existing research gaps and a few potential issues to be solved regarding 3D thin shell preforms in the near future.
文摘The manufacturing of three-dimensional textile preforms used for composites started to re-ceive much attention in the last decade.The major barriers to accelerating the transition from thelamination of two-dimensional fabrics to manufacturing integral three-dimensional near-netshaped textile preforms are high cost and database deficiency.To reduce the cost of weaving three-dimensional preforms,and make full use of the potential of conventional looms,a rig was designedwhich can convert two-dimensional woven fabric to particular three-dimensional preforms wherethe yarn is orientated in the directions of maximum stress.
文摘Three-dimensional(3 D)braided composites are a kind of advanced ones and are used in the aeronautical and astronautical fields more widely.The advantages,usages,shortages and disadvantages of 3D braided composites are analyzed,and the possible approach of improving the properties of the materials is presented,that is,a new type of 3D full 5-directional braided composites is developed.The methods of making this type of preform are proposed.It is pointed out that the four-step braiding which is the most possible to realize industrialized production almost has no effect on the composites'properties.By analyzing the simulation model,the advantages of the material compared with the 3D 4-directional and 5-directional materials are presented.Finally,a microstructural model is analyzed to lay the foundation for the future theoretical analysis of these composites.
文摘The mechanical properties of silica material in the monolithic form are ;far from acceptable levels. In this paper, 3D stitched quartz preform was used for the fiber reinforcement, and quartz fibers- reinforced silica composites were prepared by the silica sol-infiltration-sintering method. The density of the composite was up to 1.71 g/cm3 after 10 infiltration-sintering cycles. The flexural strength and the in-plane shear strength were 61.7 MPa and 20.3 MPa, respectively. The flexural stress-deflection curve exhibited mostly nonlinear behavior, which was different from that of monolithic ceramics. Because of the existence of the fiber in Z axis direction, shearing property between the different layers of 3D stitched composites were greatly enhanced. Toughness effect of the 3D stitched quartz preform was conspicuous. The as-fabricated composites showed non-catastronhic failure behavior resulting from weak fiber/matrix interface.
文摘目的:评价3D打印模型及三维预成型钛网在复杂上颌骨骨折治疗中的临床应用效果。方法:回顾性分析2017年1月—2018年10月在绍兴市中心医院口腔颌面外科治疗的6例复杂上颌骨骨折患者,头颅数据通过16层CT扫描,导入计算机辅助设计Mimics 10.01软件和Geomagic Studio 2013软件,精确分割骨折处并重建三维模型,在软件中模拟骨折复位,将骨折复位前、后的数据通过3D打印技术打印l∶l比例大小的骨折模型。术前根据实体模型完成钛网的预弯制,术后对手术效果进行评价。结果:6例患者均顺利完成手术,平均随访12个月,患者对面部轮廓及咬合关系恢复满意5例,比较满意1例。结论:对于复杂上颌骨骨折患者,3D打印模型及三维预成型钛网的使用有助于缩短手术时间,降低术后不良事件发生率,提高骨折复位效果及面部的对称性。
文摘Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.
文摘With the increasing demand of light structure composite in industry, carbon and glass fibres are more and more used, because of their light mass, high strength, high temperature endurance and erosion resistance. This paper focuses on the process of forming a preform. Up to the finished preform, the multilayer reinforced fabrics are subjected to the following procedures: pattern design, cutting and sewing. Considering the fabric properties, the 3-dimensional CAD software and sewing machines, which are generally used in the clothing industry, are also suitable for the processing of the reinforced fabrics. This study aims also to the changes of property arising from the sewing process. Bending stiffness and changes of thickness after sewing are studied. These properties will provide input data for CAD pattern design.
