scholarly journals On Factors behind the Reasonable Failure Mode of Concrete-Filled Circular Steel Tubular Composite Frame

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yang-bing Liu ◽  
Ping-ping Cui ◽  
Fang Chen
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Failure Process ◽  
Pushover Analysis ◽  
Steel Structures ◽  
Element Model ◽  
Basic Structure ◽  
Frame Structures ◽  
Steel Beam ◽  
Model Method

As the most basic structure, the concrete-filled steel tubular (CFST) frame has been widely used in various structures and systems. Compared with conventional reinforced concrete structures and steel structures, CFST structures in strong earthquake showcase more complicated strength and deformation behavior because there are many factors underlying the failure mode. Furthermore, according to the specifications at home and abroad, the corresponding design method to achieve reasonable failure modes for CFST structures has not been clarified. Based on a destructive test on steel beam-CFST plane frames under constant axial load and lateral load, the fiber mode method and solid element model method are adopted to simulate the failure process of the test frames. Based on finite element model simulations and tests, the fiber model method is proposed to carry out the pushover analysis on the CFST frame structures. The factors behind the reasonable failure mode of steel beam-concrete-filled circular steel tubular (CFCST) frame structures are analyzed. Furthermore, the law and influencing factors behind the ratio of flexural capacity of column to beam, the ratio of line stiffness of beam to column, and the ratio of axial compression on the deformation, bearing capacity, and failure modes of the structure are discussed. Some suggestions on the design of reasonable failure mode of steel beam-concrete-filled circular steel tubular (CFCST) frame structures are proposed.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

Finite Element Simulation on Failure of Elbow Impacted by Flat-Nosed Missile

2011 ◽  
Vol 105-107 ◽  
pp. 38-42
Author(s):  
Jian Liang Yu ◽  
Xing Qing Yan ◽  
Ling Chen
Keyword(s):  
Finite Element ◽  
Kinetic Energy ◽  
Failure Mode ◽  
Failure Criterion ◽  
Failure Process ◽  
Element Model ◽  
Rupture Velocity ◽  
Element Simulation ◽  
Experimental Values ◽  
Rupture Strain

Finite element model of the elbow interiorly impacted by flat-nosed missile was established using ANSYS/LS-DYNA. The Cowper-Symonds model was adopted. The rupture strain failure criterion was used to define the failure process. Numerical values were compared with experimental values obtained from the literature and the reliability of model was validated. The penetration failure mode of the elbow was analyzed. Factors of the critical rupture kinetic energy Er were acquired. It can be seen that the penetration failure mode is plugging induced by the extrusion and scraping dominated of axis stress. The effect of Do on Er can be neglected. Er increases with the increase of t/Do, Dm/t and R/Do when the missile mass m is invariable. The effect of m on Er should consider the factors of m and critical rupture velocity Vr.

Experimental Research on Failure Modes of Specimen Containing Non-Coplanar Joints

2013 ◽  
Vol 779-780 ◽  
pp. 332-336
Author(s):  
Ping Cao ◽  
Wen Cheng Fan ◽  
Ke Zhang
Keyword(s):  
Shear Strength ◽  
Failure Mode ◽  
Failure Modes ◽  
Cement Mortar ◽  
Failure Process ◽  
Jointed Rock ◽  
Important Relationship ◽  
Initial Setting ◽  
Series Of Experiments ◽  
Dip Angle

To study the failure mechanism and failure mode of jointed rock under compressive-shear, many rock-like material specimens containing non-coplanar joints were made and a series of experiments were carried out. In the experiments, mica sheets were used as joint fillings, cement mortar was selected as rock-like material. Joints were made by inserting the mica sheet in cement mortar before initial setting. Mica sheets were left down as joint fillings. The results of experiments show that the dip angles of major joint have important influence on the failure mode of specimens. And the emerging position of wing cracks which exist in the prophase of specimens failure process changes with the dip angle. The shear strength of specimens has an important relationship with the dip angle of major joints. The smallest shear strength happens in the specimen with a joint angle of 15°, while the biggest value happens in 60°.

Study on Failure Mode for Power Intake Structure under Seismic Action

2013 ◽  
Vol 438-439 ◽  
pp. 1537-1541
Author(s):  
Lin Gang Tian ◽  
Bin Bin Zhen ◽  
Hu Huang ◽  
Jing Shen
Keyword(s):  
Failure Mode ◽  
Seismic Waves ◽  
Failure Modes ◽  
Seismic Analysis ◽  
Failure Process ◽  
Early Period ◽  
Seismic Load ◽  
Seismic Action ◽  
High Intake ◽  
Ultimate Failure

This paper studies on the ultimate failure modes and bearing capacity of high intake tower under the action of seismic load based on nonlinear concrete model. By monitoring the way of crack development and failure process of the tower to study failure mode under the action of various seismic wave, we can conclud that the regional distributions of the structural crack of tower body vary with the duration of an earthquake. In the early period of earthquake, the crack has little effect on the whole structure. After duration of the earthquake, the structure forms penetrable cracks. By studying the cracks development and distribution on the structure of tower body under the action of various seismic waves, we know the failure process and failure mode of high intake tower. The conclusions provide evidence for engineering design and seismic analysis of pertinent engineering.

Fracture Pattern Comparison Research of Different Types of All-Ceramic Crown

2013 ◽  
Vol 699 ◽  
pp. 480-483
Author(s):  
Cheng Fan
Keyword(s):  
Failure Modes ◽  
Process Analysis ◽  
Failure Process ◽  
Element Model ◽  
Fracture Pattern ◽  
All Ceramic ◽  
Dimensional Finite Element ◽  
The Difference ◽  
Analysis System ◽  
Ceramic Crown

All-ceramic crown restorations are more widely used. The mechanical properties of different type of all-ceramic crown are evident different because of the differences of materials and production process. To study the failure pattern of different all-ceramic crown under load, two dimensional finite element model of three different all-ceramic crown models are constructed using the RFPA (realistic failure process analysis) system in this paper. Due to the difference of stress mismatch between different porcelain layers, it is found that the failure modes of different all-ceramic crown model are significantly different in the study. The advantage of this system is that the crack initiation, propagation and failure process of all-ceramic crown can be clearly observed and the research results provide guidance for clinical application.

Probabilistic Evaluation of Effects of Column Moment Magnification Factor on Seismic Performance of Reinforced Concrete Frames

2011 ◽  
Vol 243-249 ◽  
pp. 251-257 ◽  
Author(s):  
Ming Ji He ◽  
Chun Yang ◽  
Jian Cai ◽  
Yan Sheng Huang ◽  
Yi Wu
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Frame Structures ◽  
Rc Frame ◽  
Magnification Factor ◽  
Rc Frame Structures

Enhancing column flexural capacity is the key measure in seismic capacity design to achieve strong column-weak beam failure mode and determinate the probabilistic relation between column moment magnification factor (CMMF). In the paper the effects of column moment magnification factor on seismic performance of reinforced concrete (RC) frames are evaluated to limit the occurrence probability of column-hinging failure modes within an acceptable tolerance. Monte Carlo simulation methodology is used to calculate the probability of drift demand exceeding drift capacity of two typical frame structures with consideration of major uncertainties. And fragility curves are constructed to obtain the relationship between CMMF and probability of structural damages and assess the seismic vulnerability of RC frame structures. Results show that the seismic performance of RC frame structures can be significantly enhanced by improving CMMF. The CMMF is required to be equal to or greater than 2.0 to achieve acceptable probability of exceedance of column-hinging failure mode.

scholarly journals Failure of Rock Slope with Heterogeneous Locked Patches: Insights from Numerical Modelling

2021 ◽  
Vol 11 (18) ◽  
pp. 8585
Author(s):  
Bin Fu ◽  
Yingchun Li ◽  
Chun’an Tang ◽  
Zhibin Lin
Keyword(s):  
Slope Stability ◽  
Failure Mode ◽  
Rock Slope ◽  
Failure Modes ◽  
Process Analysis ◽  
Failure Process ◽  
Shear Loading ◽  
Constitutive Relationship ◽  
Rock Slope Stability ◽  
Geometrical Properties

Rock slope stability is commonly dominated by locked patches along a potential slip surface. How naturally heterogeneous locked patches of different properties affect the rock slope stability remains enigmatic. Here, we simulate a rock slope with two locked patches subjected to shear loading through a self-developed software, rock failure process analysis (RFPA). In the finite element method (FEM)-based code, the inherent heterogeneity of rock is quantified by the classic Weibull distribution, and the constitutive relationship of the meso-scale element is formulated by the statistical damage theory. The effects of mechanical and geometrical properties of the locked patches on the stability of the simulated rock slope are systematically studied. We find that the rock homogeneity modulates the failure mode of the rock slope. As the homogeneity degree is elevated, the failure of the locked patch transits from the locked patch itself to both the interfaces between the locked patched and the slide body and the bedrock, and then to the bedrock. The analysis of variance shows that length and strength of locked patch affect most shear strength and the peak shear displacement of the rock slope. Most of the rock slopes exhibit similar failure modes where the macroscopic cracks mainly concentrate on the interfaces between the locked patch and the bedrock and the slide body, respectively, and the acoustic events become intensive after one of the locked patches is damaged. The locked patches are failed sequentially, and the sequence is apparently affected by their relative positions. The numerically reproduced failure mode of the rock slope with locked patches of different geometrical and mechanical properties are consistent with the laboratory observations. We also propose a simple spring-slider model to elucidate the failure process of the rock slope with locked patches.

Experimental studies on seismic behavior of precast hybrid steel–concrete beam

2018 ◽  
Vol 22 (3) ◽  
pp. 670-686 ◽  
Author(s):  
Xizhi Zhang ◽  
Shaohua Zhang ◽  
Sixin Niu
Keyword(s):  
Failure Mode ◽  
Seismic Behavior ◽  
Concrete Beam ◽  
Failure Modes ◽  
Concrete Beams ◽  
Precast Concrete ◽  
Stiffness Degradation ◽  
Connection Form ◽  
Steel Beam ◽  
Deformation Curves

This study aims to investigate the seismic behavior of precast hybrid steel–concrete beams. Five full-scale beam specimens, including four precast hybrid steel–concrete beams and a conventional precast concrete beam, were tested under cyclic loading. Furthermore, a new connection form was proposed to facilitate the constructability of the steel-to-concrete connection. The main experimental parameters were the steel beam length and the longitudinal reinforcement ratio. In addition, the influence of the reduced beam section of the steel beam on seismic behavior of precast hybrid steel–concrete beams was observed and investigated. Detailed analysis was performed on the basis of the observed failure modes and the relationships obtained from the experimental data, such as hysteretic curves, deformation curves, stiffness degradation curves, energy dissipation capacity, load curvature curves, and strain development curves. Experimental results showed that the failure mode of precast hybrid steel–concrete beams was different from that of precast concrete beams. The precast hybrid steel–concrete beam retained ductility comparable to that of precast concrete beams. Generally, the initial stiffness of precast hybrid steel–concrete beams was smaller than that of precast concrete beams, but the stiffness degradation was more stable. On the basis of measured crack propagation and failure mode, deformation curves, and the development of strain in steel beams and longitudinal reinforcements, the stress between the steel beam and concrete beam can be effectively transmitted to one another by the proposed connection form.

Study of Failure Modes of Suction Anchors

2011 ◽  
Author(s):  
Qiyi Zhang ◽  
Sheng Dong
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Limit Equilibrium ◽  
Element Model ◽  
Ultimate Bearing Capacity ◽  
Engineering Practice ◽  
Element Analysis ◽  
Limit Equilibrium State

Suction foundations are widely used in deep sea and their ultimate bearing capacity which is closely related with failure modes of suction anchor at limit equilibrium state is a key technology in offshore engineering practice. Based on Coulomb friction theory, an exact finite element model is presented in this paper. On the basis of this FEM model, by use of the finite element analysis software ABAQUS, the effect of mooring point and aspect ratio of a suction anchor on the ultimate bearing capacity and its stability are researched in detail. The results show that the ultimate bearing capacity and stability of the suction anchor are affected vastly by the position of mooring point, and the variation of mooring point on the suction anchor can lead to different failure modes. Simultaneously, the results also shows that tilted rotation of the soil along the direction of the mooring force will occur when the mooring point is near the top of the suction anchor, and the soil near the bottom of the fixed anchor rotates around the center of a circle, so the failure mode is called forward-tilted rotation in this paper; A general translation slip of the soil in front of the anchor along the direction of the mooring force will occur when mooring point is below midpoint of suction anchor, so the failure mode is called the translation slip failure mode in this paper. Anticlockwise tilted rotation of the soil along the direction of mooting force will occur when the mooring point is near the bottom of the anchor, and the soil at the top of the anchor rotates around the center of a circle, so the failure mode is called backward-tilted rotation in this paper.

Failure Mechanisms of Weld Bonded Lap Joints Between Composite/Metal Adherends

2014 ◽  
Author(s):  
Lijun Li ◽  
Lingyu Sun
Keyword(s):  
Failure Mode ◽  
Adhesive Bonding ◽  
Failure Modes ◽  
Load Transfer ◽  
Engineering Application ◽  
Element Model ◽  
Simulation Method ◽  
Lap Joints ◽  
Transfer Path ◽  
The Impact

Weld-bonding, a combination of spot welding and adhesive bonding, is a primary method of joining the composite underbody to the steel body-in-white (BIW). This concept is provided by the Automotive Composites Consortium (ACC) to ensure the compatibility with the OEM assembly processes. This paper established the finite element model of the weld bonded lap joint based on the published specimen dimensions, and compared the ultimate load and failure mode with their experimental results. Their good agreements demonstrated the accuracy of the numerical model and simulation method. Using this model, the progressive failures within the joints were predicted under static tensile loading and impact loading, respectively. The impact resistant capability of this joint was evaluated and the load transfer path among the adhesives, welded spot, composite and HSS adherend was discussed. The influences of relative thickness and relative stiffness between the adhesives and the two adherends on the failure modes were studied numerically, and the map chart for failure mode prediction was provided for weld bonded lap joints of bi-materials adherends, which is helpful for engineering application.

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