Bearing Capacity Finite Element Model and Solution of High-Pressure Gas Nonmetal Glass Steel Pipeline

ICPTT 2011 ◽  
2011 ◽  
Author(s):  
Huaixin Zhang ◽  
Ying Liu ◽  
Kexi Liao
2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Qi Guo ◽  
Qing-wei Chen ◽  
Ying Xing ◽  
Ya-ning Xu ◽  
Yi Zhu

Prefabrication of composites beam reduces the construction time and makes them easily to be assembled, deconstructed, and partially repaired. The use of high-strength frictional bolt shear connectors can greatly enhance the sustainability of infrastructure. However, researches about the concrete-steel friction behavior are very limited. To provide a contribution to this area, 21 tests were conducted to measure the friction coefficient and slip stiffness with different concrete strength, steel strength, and surface treatment of steel. An effective finite element model was developed to investigate the ultimate bearing capacity and load-slip characteristics of bolt shear connection. The accuracy of the proposed finite element model is validated by the tests in this paper. The results demonstrate a positive correlation between concrete strength and friction coefficient and better performance of shot-blasted steel. It is also proved that high-strength frictional bolt has a 30% lower bearing capacity but better strength reserve and antiuplifting than the headed stud.


2019 ◽  
Vol 23 (6) ◽  
pp. 1074-1086 ◽  
Author(s):  
Tao Zhu ◽  
Hongjun Liang ◽  
Yiyan Lu ◽  
Weijie Li ◽  
Hong Zhang

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.


2013 ◽  
Vol 53 ◽  
pp. 624-631 ◽  
Author(s):  
A.B. Mohd Hadzley ◽  
R. Izamshah ◽  
A. Siti Sarah ◽  
M. Nurul Fatin

Author(s):  
MD Waquar Alam

Large displacements during excavation are regularly observed in Squeezing ground condition and Rock-burst condition with high overburden. The expected displacement has to be estimated prior to excavation to provide enough allowance for the displacements. The support system need to be well-suited through the estimated imposed strains. As the estimated displacements and thus the strains in the support depend upon the load-bearing capacity of support. The ratio of uniaxial compressive strength of rock mass to maximal insitu stress determines tunnel integrity in the weak region.This ratio estimates the requirements of initial lining to control strain to a stipulated level. The elasto-plastic theory may deliver definitive forecasts providing the strength limitations of rock masses are identified accurately. With the help of empirical analysis, the development of displacements for diverse advance rates and supports can be concluded. As a consequence, a quantitative finite element model based on an advanced built-in model is designed to analyse the load-bearing efficiency of initial lining although taking into consideration the time-dependent and non-linear material behaviour of initial lining. The time-dependent excavation mechanism of the drill-and-blast approach for tunnels guided by full face excavation is considered in the finite element model. The material parameters for the initial lining were computed based on case studies- (A Chibro-Khodri Hydropower Tunnel).


Author(s):  
Wudang Ying ◽  
Changgen Deng ◽  
Chenhui Zhang

<p>The monitoring sleeved members (MSMs) are considered with light weight, excellent load-bearing capacity, superior ductility, and can be applied in long span spatial structure to monitor the capacity of the spatial structure. This paper mainly focuses on presenting the mechanical behaviours of the MSMs based on the full-range finite element analysis. The finite element model was developed to simulate the mechanical behaviors of the MSMs, which was verified by a specimen test. Based on the verified finite element model, parametric studies were carried out to investigate the influence of the core protrusion lp, the core slenderness ratio λi, the flexural rigidity ratio β, and the gap δg between core tube and restraining tube on the mechanical behaviours of the MSMs. It is concluded that (1) lp determines the control range of the restraining tube to the core tube. Local buckling of the MSMs with lp/l≤0.0406 occurs at a relatively small axial deformation. The ultimate bearing capacity of the MSMs with lp/l≤0.0406 is generally less than that of the MSM with lp/l&gt;0.0406; (2) λi is a sensitive parameter influencing the failure mode. The smaller the core slenderness ratio λi, the less likely global buckling will occur; (3) β guarantees the control effect of the restraining tube on the core tube. β≥8.349 is needed to avoid global buckling; (4) a proper δg determining the alert moment for contact is indispensable to monitor contact status of MSMs, but it has no effect on the failure mode.</p>


Author(s):  
Shi Hui Zhou ◽  
Guo Dong ◽  
Zheng Ji Li

Experimental data obtained from full-scale experiments determines the stiffness of wedge connected of scaffold.A finite element model is developed using semi-rigid scaffold node mode.And a reasonable combination of longitudinal span,transverse span and step distance is obtained.The results accords with the relevant standard of vertical load.It provides a theoretical support for the application of wedge connected scaffold.Additionally,the study explores the safety height of the wedge connected scaffold with or without bridging.It provides a theoretical basis for technical regulations.


2020 ◽  
Vol 1 (1) ◽  
pp. 59-78
Author(s):  
Aleksandr Cherniaev ◽  
Svetlana Pavlova ◽  
Aleksandr Pavlov ◽  
Valeriy Komarov

Assessments of residual load-carrying capacity are often conducted for composite structural components that have received impact damage. The availability of a verified simulation methodology can provide significant cost savings when such assessments are required. To support the development of a reliable and accurate simulation methodology, this study investigated the predictive capabilities of a stacked solid-shell finite element model of a cylindrical composite component with a damage mechanics-based description of the intra-ply material response and a cohesive contact model used for simulation of the inter-ply behavior. Identification of material properties for the model was conducted through mechanical characterization. Special attention was paid to understanding the influence of non-physical parameters of the intra- and inter-ply material models on predicting compressive failure load of damaged composite cylinders. Calibration of the model conducted using the response surface methodology allowed for identifying rational values of the non-physical parameters. The results of simulations with the identified and calibrated finite element model showed reasonable correlation with experimental data in terms of the predicted failure loads and post-impact and post-failure damage modes. The investigated modeling technique can be recommended for evaluating the residual load-bearing capacity of flat and curved composite parts with impact damage working under the action of compressive loads.


1999 ◽  
Vol 36 (5) ◽  
pp. 793-806 ◽  
Author(s):  
K M Lee ◽  
V R Manjunath ◽  
D M Dewaikar

Laboratory model tests have been carried out using a rigid strip footing supported on dense sand overlying soft clay with and without a layer of geotextile reinforcement at the interface. The study aimed at determining the effect of geotextile reinforcement and the thickness of a sand layer on the ultimate bearing capacity and settlement characteristics of the footing resting on a granular fill - soft soil system. It was found that the bearing capacity increases with an increase in the ratio of sand thickness to footing width until it reaches a critical value, which can be considered as the optimum limit of improvement of the bearing capacity of the layered soil. The installation of a geotextile reinforcement at the interface resulted in an appreciable increase in bearing capacity and decrease in settlement of the footing. The optimum thickness of the sand layer for a geotextile-reinforced foundation was found to be 0.8 times the width of the footing, which was significantly lower than that of an unreinforced foundation. The results of the laboratory model tests were validated by a comparison with the results of a finite element analysis. The results obtained using the finite element model compared well with data obtained from the laboratory tests. Additional parametric study was carried out by the finite element model to supplement the results of the laboratory model tests. Design recommendations are given based on the results of the finite element model and laboratory model studies for a rigid footing supported on a reinforced granular fill - soft soil system. Key words: model tests, footing, bearing capacity, granular fill, clays, finite elements, geotextiles.


2010 ◽  
Vol 163-167 ◽  
pp. 3465-3473
Author(s):  
Yi Ping Tan ◽  
Jian Li ◽  
Jin Hua Zou ◽  
Hai Bo Jiang

Local scouring around the bridge pier occurs because of flow separation and the development of several vortexes around the pier. Such scour holes can cause a weakness in the bridge which may see cracks occurring on the box girders, especially during flooding. This paper presents a design scheme in which a pile underpinning technique has been adopted for such cases during research into defects in bridges. Furthermore, the finite element model has been established to evaluate the bearing capacity of the bridge before and after adopting this new measure. A large quantity of calculation data indicate that the application of the proposed method performs appropriately and plays an important role in raising the bearing capacity of bridge. The specific program bringing this into effect correctly in a renovation project is illustrated.


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