Concept Proposal and Feasibility Verification of the Annular Crossed Cable-Truss Structure

Su-Duo Xue,Renjie Liu,Xiongyan Li,Marijke Mollaert 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.4

A new concept for improving the robustness of pre-stressed spatial structures was introduced. The purpose of this concept is to avoid existing key elements by creating an alternative load path for every structural member. With this new concept, the Annular Crossed Cable-Truss Structure was proposed. How to defining the target geometry, force-finding, and designing connections for the Annular Crossed Cable-Truss Structure were illustrated by means of designing an experimental set-up. Feasibility of the structure, including self-weight, structural stiffness, and structural adaptability in asymmetric load arrangement, was discussed based on experimental results. The results show that the Annular Crossed Cable-Truss Structure can have a light self-weight, reasonable structural stiffness, and acceptable adaptability in asymmetric load arrangement. It is concluded that the Annular Crossed Cable-Truss Structure is a feasible pre-stressed spatial structure.

Risk of venous thromboembolism in Chinese pregnant women: Hong Kong venous thromboembolism study

Duo Huang,Emmanuel Wong,Ming-Liang Zuo,Pak-Hei Chan,Wen-Sheng Yue,Hou-Xiang Hu,Ling Chen,Li-Xue Yin,Xin-Wu Cui,Ming-Xiang Wu,Xi Su,Chung-Wah Siu,Jo-Jo Hai 대한혈액학회 2019 Blood Research Vol.54 No.3

BackgroundPrevious Caucasian studies have described venous thromboembolism in pregnancy; however, little is known about its incidence during pregnancy and early postpartum peri-od in the Chinese population. We investigated the risk of venous thromboembolism in a “real-world” cohort of pregnant Chinese women with no prior history of venous thromboembolism.MethodsIn this observational study, 15,325 pregnancies were identified in 14,162 Chinese women at Queen Mary Hospital, Hong Kong between January 2004 and September 2016. Demographic data, obstetric information, and laboratory and imaging data were retrieved and reviewed.ResultsThe mean age at pregnancy was 32.4±5.3 years, and the median age was 33 years (interquartile range, 29‒36 yr). Pre-existing or newly diagnosed diabetes mellitus was present in 627 women (4.1%); 359 (0.7%) women had pre-existing or newly detected hypertension. There was a small number of women with pre-existing heart disease and/or rheumatic conditions. Most deliveries (86.0%) were normal vaginal; the remaining were Cesarean section 2,146 (14.0%). The incidence of venous thromboembolism was 0.4 per 1,000 pregnancies, of which 83.3% were deep vein thrombosis and 16.7% were pul-monary embolism. In contrast to previous studies, 66.7% of venous thrombosis occurred in the first trimester.ConclusionChinese women had a substantially lower risk of venous thromboembolism during preg-nancy and the postpartum period compared to that of Caucasians. The occurrence of pregnancy-related venous thromboembolism was largely confined to the early preg-nancy period, probably related to the adoption of thromboprophylaxis, a lower rate of Cesarean section, and early mobilization.

Test and Numerical Investigation Mechanical Behavior of Cable Dome

Guojun Sun,Shuo Xiao,Su-Duo Xue 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.4

Cable dome structure is a kind of space steel structure system with stay cable, hoop cable, ridge cable and brace strut. In order to study the mechanical properties of cable dome with different stay (steel tie rod and steel cable), two 6-m-span cable dome structures were designed and manufactured. One is with steel tie rod (SR), other is with steel cable (SC). Meanwhile, two finite element models, which were identical with the solid model, were established to analyzed the mechanical properties of the cable dome and compared with the test results. The static mechanical properties of the cable domes (SC, SR) with Full-span load and Half- span load were analyzed by test. The results show that the internal forces of the two kinds of cable domes increased with the increased of Full-span load. The vertical displacement of the cable dome (SR) was smaller than that of the cable dome (SC). When the structure was under Half-span load, the stress of the two cable domes on the loading side was relatively complex, and the internal force of the rods on the loading side varies greatly, which indicating that the structure was very sensitive to the asymmetric load. The variation trend between the simulated value and the test value was consistent, which verifies the correctness of the finite element model. Furthermore, the natural frequencies of the structure with three different load state were tested by using the exciter excitation method. The results show that the natural frequencies of the two cables were dense, and the damping ratio of the cable dome (SC) structure was basically in the range of 0.0115–0.0238, and the damping ratio of the cable dome structure (SR) was basically in the range of 0.0081–0.0132, Which can provide reference for similar cable dome structures in practical projects.

Experimental Research on the Behaviour of Eccentrically loaded SRC Columns Subjected to the ISO-834 Standard Fire Including a Cooling Phase

Chao Zhang,Guang-Yong Wang,Su-Duo Xue,Hong-Xia Yu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.2

This paper presents an experiment study of the post-fire behavior of five SRC columns under combination of axial eccentrical loading and fire. The experiment phenomena and mechanical response of the SRC column specimens during experiment, specifically loading, heating, cooling and post-fire loading were observed. The residual load bearing capacity, failure modes and vertical deformation were studied. With the test program, the effects of parameters such as the load ratio, the fire duration time and the steel ratio were studied. It is shown that the effects of temperature delay become more obvious with the increase of the depth from the heated surface. Some of the SRC column specimens failed during the cooling phase. For other specimens residual deformations were observed when the furnace temperature decreased to ambient temperature. The influence of some parameters including the load ratio, the fire duration time and the steel ratio on the post-fire load bearing capacities was discussed. It can be concluded that the residual load bearing capacity of the SRC columns decreases with the increase of the fire duration time and the load ratio, and increases with the increase of the steel ratio. Finally, a finite-element analysis model was developed to simulate the behavior of the tested SRC columns.

On the plane geometry design method of the loop-free hyperbolic single-layer cable structures

Renjie Liu,Jiajia Cao,Hang Zhao,Su-Duo Xue,Guangyong Wang,Jin Liang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

The plane geometry design of the cable-net structure is the basis for the form-finding and structural design. The loop-free single-layer cable-net structure is a new cable-net scheme, but due to its special and complex shape, it is difficult to determine its plane geometry according to architectural requirements. In this paper, the moving support node method is proposed, which can quickly get the plane geometry of a loop-free single-layer cable-net structure. The form-finding is proceeded based on the existing small elastic modulus method. There are two constraints when using the moving support node method. One is that the projection of all cables is straight line, and the other is that the distance between the two cables of each support node and the inner boundary of the target is equal. The aim is to minimize the sum of the distances from all cables to the inner boundary of the target. Using the plane geometry control parameters and the plane coordinates of the support nodes as decision variables, the plane geometry closest to the target inner and outer boundaries is get through optimization analysis. According to the derivation of the formula, the plane projection shape of a loop-free single-layer cable-net structure is mainly related to three parameters, including the number of supports, the difference between the node numbers of the supports at both ends of each cable, and the target curve equations of the inner and outer boundaries. Finally, taking the roof structure of Linyi Olympic Stadium as an instance, the feasibility of the plane geometry design method of the loop-free single-layer cable-net structures based on the moving support node method is verified.