A retrofitting technology using precast steel reinforced concrete（PSRC） panels is developed to improve the seismic performance of old masonry buildings. The PSRC panels are built up as an external PSRC wall system s...A retrofitting technology using precast steel reinforced concrete（PSRC） panels is developed to improve the seismic performance of old masonry buildings. The PSRC panels are built up as an external PSRC wall system surrounding the existing masonry building. The PSRC walls are well connected to the existing masonry building, which provides enough confinement to effectively improve the ductility, strength, and stiffenss of old masonry structures. The PSRC panels are prefabricated in a factory, significantly reducing the situ work and associated construction time. To demonstrate the feasibility and mechanical effectivenss of the proposed retrofitting system, a full-scale five-story specimen was constructed. The retrofitting process was completed within five weeks with very limited indoor operation. The specimen was then tested in the lateral direction, which could potentially suffer sigifnicant damage in a large earthquake. The technical feasibility, construction workability, and seismic performance were thoroughly demonstrated by a full-scale specimen construction and pseudo-dynamic tests.展开更多
Modem dynamic tests such as networked collaborative pseudo-dynamic testing （PDT） provide new tools to study the dynamic performance of large and complex structures. In this paper, several networked collaborative PDT...Modem dynamic tests such as networked collaborative pseudo-dynamic testing （PDT） provide new tools to study the dynamic performance of large and complex structures. In this paper, several networked collaborative PDT systems established in China and abroad are introduced, including a detailed description of the first networked collaborative platform that involved the construction of a standardized demonstration procedure for networked collaborative PDT. The example is a multi-span bridge with RC piers retrofitted by FRP, and a networked structural laboratory （NetSLab） platform is used to link distributed laboratories located at several universities together. Substructure technology is also used in the testing. The characteristics, resource sharing and collaborative work of NetSLab are described, and the results illustrate that use of the NetSLab is feasible for studying the dynamic performance of multi-span bridge structures.展开更多
This paper describes an investigation of a high-strength concrete frame reinforced with high-strength rebars that was tested in the structure engineering laboratory at Shenyang Jianzhu University. The frame specimen w...This paper describes an investigation of a high-strength concrete frame reinforced with high-strength rebars that was tested in the structure engineering laboratory at Shenyang Jianzhu University. The frame specimen was pseudo- dynamically loaded to indicate three earthquake ground motions of different hazard levels, after which the test specimen was subjected to a pseudo-static loading. This paper focuses on the design, construction and experiment of the test frame and validation of the simulation models. Research shows that a high-strength concrete frame reinforced with high-strength rebars is more efficient and economical than a traditional reinforced concrete frame structure. In addition to the economies achieved by effective use of materials, research shows that the frame can provide enough strength to exceed conventional reinforced concrete frames and provide acceptable ductility. The test study provides evidence to validate the performance of a high- strength concrete frame designed according to current seismic code provisions. Based on previous test research, a nonlinear FEM analysis is completcd by using OpenSees software, The dynamic responses of the frame structure are numerically analyzed, The results of the numerical simulation show that the model can calculate the seismic responses of the frame by OpenSees. At the same time, the test provides additional opportunities to validate the performance of the simulation models.展开更多
The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and th...The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and the PC pier of the new railway project from Hetian to Ruoqiang are taken into consideration.Two kinds of 1/5-scale assembled double-column specimens are made,and the quasi-static tests are carried out.The overall seismic performance of the two spliced piers is studied,and compared in terms of failure mechanism,bearing capacity,ductility,stiffness and energy dissipation capacity.The results show that the failure modes of both GS pier and PC pier are characterized by bending.However,the specific failure location and form are different.The GS pier presents a complete hysteretic curve,large equivalent stiffness and strong energy dissipation capacity.The hysteretic area of the PC pier is small.However,it has good self-reset ability and quasi-static residual displacement.Finite element models are set up using DispBeamColumn fiber elements and ZeroLength elements.The models that are calibrated with the test data can effectively simulate the damage development under monotonic loading.The load−displacement curves are in good agreement with the backbone curves of the test results.展开更多
This paper presents an automated POCOFAN-POFRAME algorithm thatpartitions large combinational digital VLSI circuits for pseudo exhaustive testing. In thispaper, a simulation framework and partitioning technique are pr...This paper presents an automated POCOFAN-POFRAME algorithm thatpartitions large combinational digital VLSI circuits for pseudo exhaustive testing. In thispaper, a simulation framework and partitioning technique are presented to guide VLSIcircuits to work under with fewer test vectors in order to reduce testing time and todevelop VLSI circuit designs. This framework utilizes two methods of partitioningPrimary Output Cone Fanout Partitioning (POCOFAN) and POFRAME partitioning todetermine number of test vectors in the circuit. The key role of partitioning is to identifyreconvergent fanout branch pairs and the optimal value of primary input node N andfanout F partitioning using I-PIFAN algorithm. The number of reconvergent fanout andits locations are critical for testing of VLSI circuits and design for testability. Hence, theirselection is crucial in order to optimize system performance and reliability. In the presentwork, the design constraints of the partitioned circuit considered for optimizationincludes critical path delay and test time. POCOFAN-POFRAME algorithm uses theparameters with optimal values of circuits maximum primary input cone size (N) andminimum fan-out value (F) to determine the number of test vectors, number of partitionsand its locations. The ISCAS’85 benchmark circuits have been successfully partitioned,the test results of C499 shows 45% reduction in the test vectors and the experimentalresults are compared with other partitioning methods, our algorithm makes fewer testvectors.展开更多
利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力...利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力试验,分别为整体现浇墩Z1、新型插槽式连接墩P1及现有“I型”连接墩P2,并采用OpenSees有限元软件做模拟分析,与试验结果对比分析。结果表明:三个桥墩的破坏形式一致,均为弯曲破坏;Z1墩与P1墩滞回曲线呈梭形,滞回环较为饱满,且相同位移加载循环下的滞回路径较为吻合,P2墩接口处钢筋与混凝土间黏结滑移影响较大,导致滞回环面积减小,桥墩整体滞回耗能能力降低;P1墩的耗能能力较Z1墩和P2墩分别提升7.0%、10.7%,呈现峰值荷载小、失效速率慢、极限位移大、滞回耗能多的骨架趋势。试验结果与有限元模拟结果较为吻合,抗震性能参数差幅在10.0%以内,新型插槽式连接墩可应用于实际工程。展开更多
Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefor...Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefore, we evaluated a hand cream that was specially formulated for highly stressed skin with regard to its capability to reduce dry, rough, and scaly skin. The objective of this study was to conduct a controlled use test of a barrier repair cream containing pseudo-ceramide and demonstrate its efficacy for hairdressers with dry, sensitive hands and/or occupational skin disorders. A total of 30 hairdressers (29 females and 1 male, aged 20 - 67) participated in the study. All subjects suffered from dry hands. Subjects applied the test cream on their hands for 28 days (four weeks). For each subject, the skin surface topography of the hands was measured by the Surface Evaluation of Living Skin (SELS) system at day 14 (week 2) and day 28 (week 4). Dryness, scaling, cracking, redness, and itchiness were evaluated and graded by experts at week 2 and week 4, and then compared to baselines. All 30 subjects completed the study. A comparison of the changes from baseline to endpoint revealed a statistically significant reduction in skin roughness, scaling, and volume measured according to SELS. These data were confirmed by photographic documentation. The results were further supported by the expert evaluation. For the symptoms dryness and scaling, improvement could be observed in almost all regions of the hands. In addition, according to subjective assessments of overall hand skin condition and the hand cream, subjects reported clear improvement over time (p value below 0.001) and good efficacy of the product. In this study, the test hand cream showed excellent skin compatibility. Therefore, the hand cream may be effective for hairdressers with dry, sensitive hands and/or occupational skin disorders.展开更多
基金Scientific Research Fund of Institute of Engineering Mechanics,CEA under Grant No.2016A06International Science & Technology Cooperation Program of China under Grant No.2014DFA70950National Natural Science Foundation of China under Grant Nos.51378478,51161120360
文摘A retrofitting technology using precast steel reinforced concrete（PSRC） panels is developed to improve the seismic performance of old masonry buildings. The PSRC panels are built up as an external PSRC wall system surrounding the existing masonry building. The PSRC walls are well connected to the existing masonry building, which provides enough confinement to effectively improve the ductility, strength, and stiffenss of old masonry structures. The PSRC panels are prefabricated in a factory, significantly reducing the situ work and associated construction time. To demonstrate the feasibility and mechanical effectivenss of the proposed retrofitting system, a full-scale five-story specimen was constructed. The retrofitting process was completed within five weeks with very limited indoor operation. The specimen was then tested in the lateral direction, which could potentially suffer sigifnicant damage in a large earthquake. The technical feasibility, construction workability, and seismic performance were thoroughly demonstrated by a full-scale specimen construction and pseudo-dynamic tests.
基金The Key Project of the Major Research Plan of Natural Science Foundation of China Under Grant No.90715036the Key Project of the Natural Science Foundation of China Under Grant No.50338020
文摘Modem dynamic tests such as networked collaborative pseudo-dynamic testing （PDT） provide new tools to study the dynamic performance of large and complex structures. In this paper, several networked collaborative PDT systems established in China and abroad are introduced, including a detailed description of the first networked collaborative platform that involved the construction of a standardized demonstration procedure for networked collaborative PDT. The example is a multi-span bridge with RC piers retrofitted by FRP, and a networked structural laboratory （NetSLab） platform is used to link distributed laboratories located at several universities together. Substructure technology is also used in the testing. The characteristics, resource sharing and collaborative work of NetSLab are described, and the results illustrate that use of the NetSLab is feasible for studying the dynamic performance of multi-span bridge structures.
基金Liaoning Provincial Natural Science Foundation of China Under Grant No. 20052005
文摘This paper describes an investigation of a high-strength concrete frame reinforced with high-strength rebars that was tested in the structure engineering laboratory at Shenyang Jianzhu University. The frame specimen was pseudo- dynamically loaded to indicate three earthquake ground motions of different hazard levels, after which the test specimen was subjected to a pseudo-static loading. This paper focuses on the design, construction and experiment of the test frame and validation of the simulation models. Research shows that a high-strength concrete frame reinforced with high-strength rebars is more efficient and economical than a traditional reinforced concrete frame structure. In addition to the economies achieved by effective use of materials, research shows that the frame can provide enough strength to exceed conventional reinforced concrete frames and provide acceptable ductility. The test study provides evidence to validate the performance of a high- strength concrete frame designed according to current seismic code provisions. Based on previous test research, a nonlinear FEM analysis is completcd by using OpenSees software, The dynamic responses of the frame structure are numerically analyzed, The results of the numerical simulation show that the model can calculate the seismic responses of the frame by OpenSees. At the same time, the test provides additional opportunities to validate the performance of the simulation models.
基金Project(N2018G034)supported by China Railway Corporation。
文摘The comparative research on the seismic performance of grouted sleeve connected pier(GS)and prestressed precast segmental concrete pier(PC)is mostly carried out by numerical simulation.In this study,the GS pier and the PC pier of the new railway project from Hetian to Ruoqiang are taken into consideration.Two kinds of 1/5-scale assembled double-column specimens are made,and the quasi-static tests are carried out.The overall seismic performance of the two spliced piers is studied,and compared in terms of failure mechanism,bearing capacity,ductility,stiffness and energy dissipation capacity.The results show that the failure modes of both GS pier and PC pier are characterized by bending.However,the specific failure location and form are different.The GS pier presents a complete hysteretic curve,large equivalent stiffness and strong energy dissipation capacity.The hysteretic area of the PC pier is small.However,it has good self-reset ability and quasi-static residual displacement.Finite element models are set up using DispBeamColumn fiber elements and ZeroLength elements.The models that are calibrated with the test data can effectively simulate the damage development under monotonic loading.The load−displacement curves are in good agreement with the backbone curves of the test results.
文摘This paper presents an automated POCOFAN-POFRAME algorithm thatpartitions large combinational digital VLSI circuits for pseudo exhaustive testing. In thispaper, a simulation framework and partitioning technique are presented to guide VLSIcircuits to work under with fewer test vectors in order to reduce testing time and todevelop VLSI circuit designs. This framework utilizes two methods of partitioningPrimary Output Cone Fanout Partitioning (POCOFAN) and POFRAME partitioning todetermine number of test vectors in the circuit. The key role of partitioning is to identifyreconvergent fanout branch pairs and the optimal value of primary input node N andfanout F partitioning using I-PIFAN algorithm. The number of reconvergent fanout andits locations are critical for testing of VLSI circuits and design for testability. Hence, theirselection is crucial in order to optimize system performance and reliability. In the presentwork, the design constraints of the partitioned circuit considered for optimizationincludes critical path delay and test time. POCOFAN-POFRAME algorithm uses theparameters with optimal values of circuits maximum primary input cone size (N) andminimum fan-out value (F) to determine the number of test vectors, number of partitionsand its locations. The ISCAS’85 benchmark circuits have been successfully partitioned,the test results of C499 shows 45% reduction in the test vectors and the experimentalresults are compared with other partitioning methods, our algorithm makes fewer testvectors.
文摘利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力试验,分别为整体现浇墩Z1、新型插槽式连接墩P1及现有“I型”连接墩P2,并采用OpenSees有限元软件做模拟分析,与试验结果对比分析。结果表明:三个桥墩的破坏形式一致,均为弯曲破坏;Z1墩与P1墩滞回曲线呈梭形,滞回环较为饱满,且相同位移加载循环下的滞回路径较为吻合,P2墩接口处钢筋与混凝土间黏结滑移影响较大,导致滞回环面积减小,桥墩整体滞回耗能能力降低;P1墩的耗能能力较Z1墩和P2墩分别提升7.0%、10.7%,呈现峰值荷载小、失效速率慢、极限位移大、滞回耗能多的骨架趋势。试验结果与有限元模拟结果较为吻合,抗震性能参数差幅在10.0%以内,新型插槽式连接墩可应用于实际工程。
文摘Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefore, we evaluated a hand cream that was specially formulated for highly stressed skin with regard to its capability to reduce dry, rough, and scaly skin. The objective of this study was to conduct a controlled use test of a barrier repair cream containing pseudo-ceramide and demonstrate its efficacy for hairdressers with dry, sensitive hands and/or occupational skin disorders. A total of 30 hairdressers (29 females and 1 male, aged 20 - 67) participated in the study. All subjects suffered from dry hands. Subjects applied the test cream on their hands for 28 days (four weeks). For each subject, the skin surface topography of the hands was measured by the Surface Evaluation of Living Skin (SELS) system at day 14 (week 2) and day 28 (week 4). Dryness, scaling, cracking, redness, and itchiness were evaluated and graded by experts at week 2 and week 4, and then compared to baselines. All 30 subjects completed the study. A comparison of the changes from baseline to endpoint revealed a statistically significant reduction in skin roughness, scaling, and volume measured according to SELS. These data were confirmed by photographic documentation. The results were further supported by the expert evaluation. For the symptoms dryness and scaling, improvement could be observed in almost all regions of the hands. In addition, according to subjective assessments of overall hand skin condition and the hand cream, subjects reported clear improvement over time (p value below 0.001) and good efficacy of the product. In this study, the test hand cream showed excellent skin compatibility. Therefore, the hand cream may be effective for hairdressers with dry, sensitive hands and/or occupational skin disorders.
