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Study on failure modes and calculation method of the cast steel joint with branches in treelike structure

Chen Feng, Sun Yun, Sun Shuxuan, Song Da, Liu Yangbing

Archives of Civil Engineering

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2024

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Vol. 70, nr 1

589--604

EN

The treelike structure links members and transfers loads via its solitary cast steel joint with branches. Therefore, the joint’s bearing capacity significantly affects the treelike structure’s stability, security, and economics. This paper utilized experimental verification and numerical modeling to examine the mechanical behavior of cast-steel joints with branches in the treelike structure under various loading conditions. Then, researchers investigated the failure process and mechanism of joints, and the three most common failure modes were outlined. Furthermore, the researchers proposed the bearing capacity calculation formula based on the common failure modes. The results show that the three common failure modes of the cast-steel joints with branches under different loading conditions are the failure in the joint core area under the axial load, the failure in the main pipe compression side under eccentric load, and the failure in the compression side of the single branch pipe root when the single branch pipe is under the uneven load. The suggested empirical calculation method can serve as a reference point for similar engineering practices design.

2

Analysis of temperature-field and stress-field of steel plate concrete composite shear wall in early stage of construction

Sun Yun, Guo Yaojie

Archives of Civil Engineering

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2021

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Vol. 67, nr 1

351--366

EN

To study the influence of temperature field and stress field on the cracking of the small thickness steel plate concrete composite shear wall (SPCW) in the early stage of construction. The temperature field and stress field of a 400 mm thickness SPCW was monitored and simulated through experimental research and numerical simulation. Moreover, a series of parameter analyses were carried out by using ANSYS to investigate the distribution of temperature field and stress field of SPCW. Based on the analysis results, some suggestions are put forward for controlling the cracking of SPCW in the early stage of construction. The results show that the temperature stress of 400 mm thickness SPCW in the early stage of construction is small, and there is no crack on the wall surface. For SPCW with thickness less than 800mm, the temperature stress caused by hydration heat in the early stage of construction is small, and the wall will not crack. The parameters such as wall thickness, steel plate thickness, boundary condition and stud space significantly influence the temperature field and stress field distribution of the small thickness SPCW in the early stage of construction, and reasonable maintenance measures can avoid cracking.

3

Analysis of gallic acid and ellagic acid in leaves of Elaeagnus angustifolia L. from different habitats and times in Xinjiang by HPLC with cluster analysis

Sun Yun, Liu Jiajia, Bayertai, Tang Shasha, Zhou Xiaoying

Acta Chromatographica

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2021

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Vol. 33, no. 2

195--201

EN

Objective: To determine the levels of gallic acid and ellagic acid by using high-performance liquid chromatography (HPLC) with R software hierarchical cluster analysisin Elaeagnus angustifolia L. gathered from different locations in Xinjiang. Methods: A chromatographic column Diamonsil C18 with a size of 4.63250 mm and 5 mm was used with methanol as A and 0.1% phosphoric acid aqueous solution as B as the mobile phase. The flow rate was 1 mL/min for the gradient elution and the injection volume was 5 mL. HPLC was performed with a detection wavelength of 260 nm and chromatographic column of 35 8C. In addition, R software hierarchical clustering method was used for studying the levels of gallic acid and ellagic acid in E. angustifolia L. from 10 areas. Results: Gallic acid and ellagic acid showed a good linear relationship between 7.375 and 236 mg/mL with a correlation coefficient of 0.9999, and between 3.625 and 116 mg/mL with a correlation coefficient of 0.9999 respectively. The average recovery values were 103.98 and 101.57%, and the Relative Standard Deviation (RSD) values were 1.92 and 1.47%. Conclusion: Differences in the levels of gallic acid and ellagic acid in E. angustifolia L. leaves from different areas in Xinjiang showed that both were the highest in Kuitun.