Parametric Study on Cyclic Behavior of Modular Assembly Composite Walls with Connection to Boundary Beam

Tong Ou,Dayang Wang,Yongshan Zhang,Hao Li 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.5

This study focuses on the investigation of seismic performance of modular assembly composite shear wall (MACW) system, which is connected to boundary beams only. The fi nite element method is employed to establish the numerical model of the MACW system and experimental data is adopted to validate the simulation. To clearly show the seismic performance of the system, seven design parameters with 36 computational cases, including height-to-span and height-to-thickness ratios of steel plate, bolt spacing, spacing between the concrete plate and connection steel plate, thicknesses of the connection steel plate and concrete plate, and the number of composite wall modules, are discussed on mechanical property and energy dissipation capacity in details. The results show that ratios of height-to-span and height-to-thickness have a signifi cant infl uence on mechanical bearing and energy dissipation properties in comparison to the other fi ve parameters. Combining systematic seismic behaviors, such as hysteresis property, out-of-plane displacement, and equivalent damping ratio, the optimal values of the above seven parameters are recommended to be 2, 600, 100, 30, 8, 50, and 2 mm respectively. Stiff ness ratios between the post-yield and initial stiff ness of all the 36 models are mainly in the range of (2.6%, 5.5%).

Experimental Study on Mechanical Properties of Continuous Welding Stainless Steel Roof System under Temperature Effect

Mingming Wang,Tong Ou,Zhiyong Xin,Dayang Wang,Yongshan Zhang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

Stainless steel is used as a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during temperature action. This study focuses on the temperature effect of a continuous welded stainless steel roof (CWSSR) system and analyzes the stress distribution of plate rib (PR), plate surface (PS), and support (SU), and the horizontal and vertical displacement. Furthermore, the thermal action of the CWSSR system is comprehensively analyzed considering different loading rates, constant temperature time, and the cycle number. Research results show that the stress concentration and thermal expansion of the CWSSR system are obvious, and fatigue damage occurs under long-term temperature action. The responses of the CWSSR system are greatly influenced by the loading rate and the cycle number but are less influenced by the constant temperature time. Loading rate and the cycle number mainly affect the plate surface stress and vertical displacement. The plate surface stress and vertical displacement peak increased by 34.6% and 29.6% with the loading rate, and changed by 32.4% and 42.5% with the cycle number. Cyclic loading reduces support tensile capacity by 4.4%. The research results can provide reference for the design and application of temperature field resistance of the CWSSR system.

Mechanical Behavior of Nine Tree-Pool Joints Between Large Trees and Buildings

Wang Dayang,Liu Mingqi,Ou Tong,Zhang Yongshan 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

Nine types of tree-pool joints designed to plant large trees on building structures were proposed in this study. Solid finite elementmodel considering plastic damage constitutive relationship for the tree-pool joints were built using ABAQUS software platform. Based on comparative analysis of six different mesh generation methods of the 3D tree-pool joint model, an optimized meshgeneration method was determined and verified considering both the calculation time and accuracy. The mechanical behavior of thenine tree-pool joints, such as peak tension/compression stress, hysteretic energy dissipation performance, plastic damageperformance and corresponding crack development process, were studied in detail under horizontal and vertical loads. The resultsshow that the tree-pool joints with steel strengthened form and composite strengthened form have superior horizontal and verticalbearing capacity. Similarly, they also have stable hysteretic energy dissipation performance, minimal plastic damage and crackdevelopment relatively in vertical ultimate load. However, the tree-pool joints with other strengthened forms, such as forms of innerbeamand inner-beam combined with ring bracket, show poor mechanical properties. Although there is a certain degree ofperformance improvement for these tree-pool joints relative to non-strengthened joints, narrow hysteretic curves, apparent strength/stiffness degradation characteristics, extensive material damage and crack development can be found. Results of this paper do shinesome lights on how to design reasonable and reliable tree-pool joints in building structures.

Wind resistance performance of a continuous welding stainless steel roof under static ultimate wind loading with testing and simulation methods

DaYang Wang,Zhendong Zhao,Tong Ou,Zhiyong Xin,Mingming Wang,Yongshan Zhang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.1

Ultrapure ferritic stainless steel provides a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during wind excitation. This study focuses on the wind-resistant capacity of a new continuous welding stainless steel roof (CWSSR) system. Full-scale testing on the welding joints and the CWSSR system is performed under uniaxial tension and static ultimate wind uplift loadings, respectively. A finite element model is developed with mesh refinement optimization and is further validated with the testing results, which provides a reliable way of investigating the parameter effect on the wind-induced structural responses, namely, the width and thickness of the roof sheeting and welding height. Research results show that the CWSSR system has predominant wind-resistant performance and can bear an ultimate wind uplift loading of 10.4 kPa without observable failures. The welding joints achieve equivalent mechanical behaviors as those of base material is produced with the current of 65 A. Independent structural responses can be found for the roof sheeting of the CWSSR system, and the maximum displacement appears at the middle of the roof sheeting, while the maximum stress appears at the connection supports between the roof sheeting with a significant stress concentration effect. The responses of the CWSSR system are greatly influenced by the width and thickness of the roof sheeting but are less influenced by the welding height. Ultrapure ferritic stainless steel provides a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during wind excitation. This study focuses on the wind-resistant capacity of a new continuous welding stainless steel roof (CWSSR) system. Full-scale testing on the welding joints and the CWSSR system is performed under uniaxial tension and static ultimate wind uplift loadings, respectively. A finite element model is developed with mesh refinement optimization and is further validated with the testing results, which provides a reliable way of investigating the parameter effect on the wind-induced structural responses, namely, the width and thickness of the roof sheeting and welding height. Research results show that the CWSSR system has predominant wind-resistant performance and can bear an ultimate wind uplift loading of 10.4 kPa without observable failures. The welding joints achieve equivalent mechanical behaviors as those of base material is produced with the current of 65 A. Independent structural responses can be found for the roof sheeting of the CWSSR system, and the maximum displacement appears at the middle of the roof sheeting, while the maximum stress appears at the connection supports between the roof sheeting with a significant stress concentration effect. The responses of the CWSSR system are greatly influenced by the width and thickness of the roof sheeting but are less influenced by the welding height

Glia maturation factor beta deficiency protects against diabetic osteoporosis by suppressing osteoclast hyperactivity

Shi Si,Gu Huijie,Xu Jinyuan,Sun Wan,Liu Caiyin,Zhu Tong,Wang Juan,Gao Furong,Zhang Jieping,Ou Qingjian,Jin Caixia,Xu Jingying,Chen Hao,Li Jiao,Xu Guotong,Tian Haibin,Lu Lixia 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Excessive osteoclast activation, which depends on dramatic changes in actin dynamics, causes osteoporosis (OP). The molecular mechanism of osteoclast activation in OP related to type 1 diabetes (T1D) remains unclear. Glia maturation factor beta (GMFB) is considered a growth and differentiation factor for both glia and neurons. Here, we demonstrated that Gmfb deficiency effectively ameliorated the phenotype of T1D-OP in rats by inhibiting osteoclast hyperactivity. In vitro assays showed that GMFB participated in osteoclast activation rather than proliferation. Gmfb deficiency did not affect osteoclast sealing zone (SZ) formation but effectively decreased the SZ area by decreasing actin depolymerization. When GMFB was overexpressed in Gmfb-deficient osteoclasts, the size of the SZ area was enlarged in a dose-dependent manner. Moreover, decreased actin depolymerization led to a decrease in nuclear G-actin, which activated MKL1/SRF-dependent gene transcription. We found that pro-osteoclastogenic factors (Mmp9 and Mmp14) were downregulated, while anti-osteoclastogenic factors (Cftr and Fhl2) were upregulated in Gmfb KO osteoclasts. A GMFB inhibitor, DS-30, targeting the binding site of GMFB and Arp2/3, was obtained. Biocore analysis revealed a high affinity between DS-30 and GMFB in a dose-dependent manner. As expected, DS-30 strongly suppressed osteoclast hyperactivity in vivo and in vitro. In conclusion, our work identified a new therapeutic strategy for T1D-OP treatment. The discovery of GMFB inhibitors will contribute to translational research on T1D-OP.