An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSC. Marc was used in the simulation using implicit static arithmetic. The whole rolling process ...An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSC. Marc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elastic-plastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The on-line experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient.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
喷射3D打印喷口与受喷面的间距空间可解决3D打印和钢筋协同建造的问题。本工作基于协同连续布筋和喷射3D打印混凝土工艺,提出喷射3D打印微筋混凝土的设计方法,研究了不同微筋直径(0.6、0.8、1.0 mm)和根数(1—4)对喷射3D打印微筋混凝土...喷射3D打印喷口与受喷面的间距空间可解决3D打印和钢筋协同建造的问题。本工作基于协同连续布筋和喷射3D打印混凝土工艺,提出喷射3D打印微筋混凝土的设计方法,研究了不同微筋直径(0.6、0.8、1.0 mm)和根数(1—4)对喷射3D打印微筋混凝土抗弯性能的影响规律。试验结果表明,微筋可显著提升打印混凝土的抗弯强度和韧性,对比未增强组(D0试样),喷射3D打印微筋混凝土的抗弯强度和弯曲位移分别最高提升了800%和2 076.47%。此外,基于喷射3D打印的高速喷压和逐层打印特性,微筋与喷射混凝土界面粘结密实,进一步保证了喷射3D打印微筋混凝土的抗弯性能和结构整体性。本工作打印了尺寸为1 300 mm (Z)×800 mm (X)×86 mm (Y)的异形火炬结构,验证了喷射3D打印微筋混凝土系统的实用性,为3D打印钢筋混凝土结构的制备及在大尺寸结构中的应用提供了一定的参考。展开更多
基金Item Sponsored by Youth Science Technology Elitist Foundation of Dalian Local Government (2001-122)
文摘An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSC. Marc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elastic-plastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The on-line experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient.
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.
文摘喷射3D打印喷口与受喷面的间距空间可解决3D打印和钢筋协同建造的问题。本工作基于协同连续布筋和喷射3D打印混凝土工艺,提出喷射3D打印微筋混凝土的设计方法,研究了不同微筋直径(0.6、0.8、1.0 mm)和根数(1—4)对喷射3D打印微筋混凝土抗弯性能的影响规律。试验结果表明,微筋可显著提升打印混凝土的抗弯强度和韧性,对比未增强组(D0试样),喷射3D打印微筋混凝土的抗弯强度和弯曲位移分别最高提升了800%和2 076.47%。此外,基于喷射3D打印的高速喷压和逐层打印特性,微筋与喷射混凝土界面粘结密实,进一步保证了喷射3D打印微筋混凝土的抗弯性能和结构整体性。本工作打印了尺寸为1 300 mm (Z)×800 mm (X)×86 mm (Y)的异形火炬结构,验证了喷射3D打印微筋混凝土系统的实用性,为3D打印钢筋混凝土结构的制备及在大尺寸结构中的应用提供了一定的参考。
基金Foundation of National Key Laboratory for Precision Hot Processing of Metalsrogram for Changjiang Scholars and Innovative Research Team in University~~
