Qifeng Shan^1,2, Ming Mao², Yushun Li^3,*

Journal of Renewable Materials, Vol.12, No.1, pp. 149-166, 2024, DOI:10.32604/jrm.2023.029445

Abstract A theoretical analysis of upward deflection and midspan deflection of prestressed bamboo-steel composite beams is presented in this study. The deflection analysis considers the influences of interface slippage and shear deformation. Furthermore, the calculation model for flexural capacity is proposed considering the two stages of loading. The theoretical results are verified with 8 specimens considering different prestressed load levels, load schemes, and prestress schemes. The results indicate that the proposed theoretical analysis provides a feasible prediction of the deflection and bearing capacity of bamboo-steel composite beams. For deflection analysis, the method considering the slippage and shear deformation provides better accuracy.… More >

Kexin Zhang^*, Tianyu Qi, Dachao Li, Xingwei Xue, Yanfeng Li

Structural Durability & Health Monitoring, Vol.16, No.1, pp. 53-80, 2022, DOI:10.32604/sdhm.2021.016130

Abstract This paper presents the method of reinforcing main girder of reinforced concrete cable-stayed bridge with prestressed steel strands. To verify the effectiveness of external prestressed strand reinforcement method. Static load tests and health monitoring-based assessment were carried out before and after reinforcement. Field load test shows that the deflection and stress values of the main girder are reduced by 10%~20% after reinforcement, and the flexural strength and stiffness of the strengthened beam are improved. The deflection and strain data of health monitoring of the specified section are collected. The deflection of the second span is 4 mm~10 mm, the strain… More >

Nan Guo¹, Jing Ren¹, Ling Li^1,*, Yan Zhao², Mingtao Wu¹

Journal of Renewable Materials, Vol.10, No.1, pp. 183-201, 2022, DOI:10.32604/jrm.2021.015756

Abstract Due to creep characteristics of wood, long-term loading can cause a significant stress loss of steel bars in reinforced glulam beams and high long-term deflection of the beam midspan. In this study, 15 glulam beams were subjected to a 90-day long-term loading test, and the effects of long-term loading value, reinforcement ratio and prestress level on the stress of steel bars, midspan long-term deflection, and other parameters were compared and analyzed. The main conclusions drawn from this study were that the long-term deflection of the reinforced glulam beams accounted for 22.5%, 20.6%, and 18.2% of the total deflection respectively when… More >

Nan Guo^1,*, Huajing Xiong¹, Mingtao Wu¹, Hongliang Zuo¹, Fengguo Jiang², Xiaofeng Hou³, Dabo Xin¹

Structural Durability & Health Monitoring, Vol.14, No.3, pp. 229-248, 2020, DOI:10.32604/sdhm.2020.09104

Abstract Creep is an important characteristic of bamboo and wood materials under long-term loading. This paper aims to study the long-term bending behaviour of prestressed glulam bamboo-wood beam (GBWB). For this, 14 pre-stressed GBWBs were selected and subjected to a long-term loading test for 60 days. Then, a comparative analysis was performed for the effects of pretension values, the number of pre-stressed wires, and long-term load on the stress variation of the steel wire and the long-term deflection of the beam midspan. The test results showed that with the number of prestressed wires increasing, the total stress of the steel wire… More >

Chengquan Wang¹, Yonggang Shen^2,*, Yun Zou¹, Tianqi Li¹, Xiaoping Feng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 75-93, 2018, DOI:10.3970/cmes.2018.114.075

Abstract The failure behavior of the precast prestressed concrete T girder was investigated by destructive test and finite-element analysis, and the mid-span deflection, girder stiffness and the variation of the cross section strain in the loading process were obtained, and the mechanical properties, mechanical behavior, elastic and plastic behavior and ultimate bearing capacity of T girder with large span were revealed. Furthermore, the relationship between the beam stiffness degradation, the neutral axis in cross-section, steel yielding and concrete cracking are investigated and analyzed. A method was proposed to predict the residual bearing capacity of a bridge based on the variation of… More >

Jianglin Xu, Zhi Sun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 63-64, 2011, DOI:10.3970/icces.2011.018.063

Abstract The measurement of residue prestress force is one main issue for condition and performance assessment of prestressed concrete beam bridge. This paper proposes a vibration based parameter estimation technique for this purpose. Under given form external excitation, beam velocity responses at multiple points are collected firstly. The prestress force of the beam is then identified based on the minimization of the least square difference between the measured response and the baseline response. A numerical study on a beam of variant length, subjected to a constant prestress force with variant eccentricity, is conducted to show the effect of prestress force and… More >

X.H. Du, X.P. Shen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.3, pp. 81-82, 2011, DOI:10.3970/icces.2011.016.081

Abstract Aim of this paper is to simulate the fluid-structure interaction of liquefied natural gas (LNG) prestressed storage tank under seismic influence. The coupled Eulerian-Lagrangian (CEL) analysis technique is used to simulate the hydrodynamic interaction between LNG and the cylinder of LNG prestressed storage tank. The 3-D model of LNG has been dispersed by Eulerian mesh which is different from traditional added mass analysis method. Meanwhile, both of the 3-D models of prestressed rebar and concrete structure are dispersed by Lagrangian mesh. Following conclusions are obtained: 1) Natural frequency of the whole model has been obtained by using the Block Lanczos… More >

Shaohua Hu^*, Ning Wang^†

Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 49-60, 2006, DOI:10.3970/mcb.2006.003.049

Abstract One fundamental question in cell biology is how mechanical stresses are distributed inside the cytoplasm. Recently we have developed a synchronous detection approach to map cytoplasmic displacements and stresses using yellow fluorescent protein tagged mitochondria as fiducial markers of the cytoskeleton (CSK) in response to a localized load applied via an RGD-coated magnetic bead (7). We have shown that stresses are propagated to remote sites in the cytoplasm, a finding that contradicts continuum model predictions. Here we show that long distance force propagation in the cytoplasm was abolished when the contractile prestress in the CSK was lowered by relaxing agents… More >

S.D. Akbarov^1,2, N. Yahnioglu³, U. Babuscu Yesil³

CMC-Computers, Materials & Continua, Vol.28, No.2, pp. 147-164, 2012, DOI:10.3970/cmc.2012.028.147

Abstract This paper presents an analysis of the forced vibration of an initially stressed rectangular composite plate containing two neighboring cylindrical cavities. The initial stresses are caused by stretching or compressing of the plate with uniformly distributed normal static forces acting on the two opposite end-planes which are parallel to the central axes of the aforementioned cylindrical cavities. The influence of the initial stresses on the stress concentration around the cavities caused by the additional uniformly distributed time harmonic forces acting on the upper face plane of the plate are given. The considered problem is formulated within the framework of the… More >

Liang Wu¹, Xiaorui Xiang¹, Yang Chen¹, Karrech Ali^2,*, Junru Zhou^1,*, Ming Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 421-443, 2019, DOI:10.32604/cmes.2019.05218

Abstract During the excavation of deep rock, a sudden change in boundary conditions will cause the in-situ stress on the excavation surface to release instantaneously. This disturbance propagates in the form of an unloading stress wave, which will enlarge the damage field of surrounding rock. In this paper, the dynamic unloading problem of the in-situ stress in deep rock excavation is studied using theoretical, numerical, and experimental methods. First, the dynamic unloading process of rock is analyzed through adopting the wave equation, and the equivalent viscous damping coefficient of the material is taken into consideration. Calculations show that there is significant… More >