scholarly journals Numerical Simulation of Dynamic Response and Evaluation of Flexural Damage of RC Columns under Horizontal Impact Load

2021 ◽  
Vol 11 (23) ◽  
pp. 11223
Author(s):  
Bin Hu ◽  
Jian Cai ◽  
Jiabin Ye
Keyword(s):  
Static Load ◽  
Impact Load ◽  
Bending Moment ◽  
Internal Force ◽  
Displacement Curve ◽  
Fe Model ◽  
Damage State ◽  
Rc Columns ◽  
Equivalent Static Load ◽  
The Impact

By using the ABAQUS finite element (FE) model, which has been verified by experiments, the deformation and internal force changes of RC columns during the impact process are investigated, and a parametric analysis is conducted under different impact kinetic energies Ek. According to the development path of the bottom bending moment-column top displacement curve under impact, the member is in a slight damage state when the curve rebounds before reaching the peak and in a moderate or severe damage state when the curve exceeds the peak, in which case the specific damage state of the member needs to be determined by examining whether there is a secondary descending stage in the curve. Accordingly, a qualitative method for evaluating the bending failure of RC column members under impact is obtained. In addition, the damage state of RC columns under impact can also be quantitatively evaluated by the ratio of the equivalent static load Feq and the ultimate static load-bearing capacity Fsu.

scholarly journals Failure Characteristics of Joint Bolts in Shield Tunnels Subjected to Impact Loads from a Derailed Train

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Qixiang Yan ◽  
Zhixin Deng ◽  
Yanyang Zhang ◽  
Wenbo Yang
Keyword(s):  
Impact Load ◽  
Numerical Study ◽  
Design Method ◽  
Shield Tunnel ◽  
Failure Behavior ◽  
Impact Loads ◽  
Fe Model ◽  
Fe Modelling ◽  
Bolt Failure ◽  
The Impact

Impact loads generated by derailed trains can be extremely high, especially in the case of heavy trains running at high speeds, which usually cause significant safety issues to the rail infrastructures. In shield tunnels, such impact loads may not only cause the damage and deformation of concrete segments, but also lead to the failure of segmental joint bolts. This paper presents a numerical study on the failure behavior of segmental joint bolts in the shield tunnel under impact loading resulting from train derailments. A three-dimensional (3D) numerical model of a shield tunnel based on the finite element (FE) modelling strategy was established, in which the structural behavior of the segmental joint surfaces and the mechanical behavior of the segmental joint bolts were determined. The numerical results show that the occurrence of bolt failure starts at the joints near the impacted segment and develops along the travel direction of train. An extensive parametric study was subsequently performed and the influences of the bolt failure on the dynamic response of the segment were investigated. In particular, the proposed FE model and the analytical results will be used for optimizing the design method of the shield tunnel in preventing the failure of the joint bolts due to the impact load from a derailed HST.

Random Seismic Response Analysis of Leaning-Type Arch Bridge

2011 ◽  
Vol 378-379 ◽  
pp. 332-336
Author(s):  
Yong He Li ◽  
Ai Rong Liu ◽  
Qi Cai Yu ◽  
Pan Tang ◽  
Fang Jie Cheng
Keyword(s):  
Bending Moment ◽  
Internal Force ◽  
Response Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Arch Bridge ◽  
Space Truss ◽  
Out Of Plane ◽  
Plane Bending ◽  
The Impact

With an example of steel pipe concrete leaning-type arch bridge, space truss system Finite Element Analysis model is constructed using the Ruiz-Penzien random seismic vibration power spectrum model. The impact of inclined arch rib angle and the number of cross brace between main and stable arch ribs on the seismic internal force response under lateral random seismic excitation is also studied in this research. Research finding shows, the in-plane bending moment of main arch rib gradually increases with increasing stable arch rib angle and cross brace, whereas the out-of-plane bending moment and axial force display a decreasing trend. In general, this indicates that increasing stable arch rib angle and number of cross brace improves the lateral aseismatic performance of leaning-type arch bridge.

Energy Absorption of All-Metallic Corrugated Sandwich Cylindrical Shells Subjected to Axial Compression

2020 ◽  
Vol 87 (12) ◽  
Author(s):  
Pengbo Su ◽  
Bin Han ◽  
Mao Yang ◽  
Zhongnan Zhao ◽  
Feihao Li ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
High Speed ◽  
Impact Load ◽  
Cylindrical Shells ◽  
Dynamic Effect ◽  
Absorption Capacity ◽  
Amplification Coefficient ◽  
Displacement Curve ◽  
The Impact

Abstract The energy adsorption properties of all-metallic corrugated sandwich cylindrical shells (CSCSs) subjected to axial compression loading were investigated by the method combining experiments, finite element (FE) simulations, and theoretical analysis. CSCS specimens manufactured using two different methods, i.e., high-speed wire-cut electric discharge machining (HSWEDM) and extrusion, were tested under axial compression. While specimens fabricated separately by HSWEDM and extrusion both exhibited a stable crushing behavior, the extruded ones were much more applicable as lightweight energy absorbers because of their good energy absorption capacity, repeatability, and low cost. The numerically simulated force–displacement curve and the corresponding deformation morphologies of the CSCS compared well with those obtained from experiments. The specific folding deformation mode was revealed from both experiments and simulations. Subsequently, based upon the mode of folding deformation, a theoretical model was established to predict the mean crushing force of the CSCS construction. It was demonstrated that CSCSs with more corrugated units, smaller value of tc/tf and W/Ro could dissipate more impact energy. Such sandwich cylindrical shells exhibited better energy absorption than monolithic cylindrical shells, with an increase of at least 30%. Ultimately, the dynamic effect under the impact load was further evaluated. The dynamic amplification coefficient of CSCS decreased with the increase of the wall thickness.

Impact Response and Simulation of Damaged Ulna With Internal Fixation

2012 ◽  
Vol 28 (3) ◽  
pp. 324-334
Author(s):  
Cameron Coates ◽  
Priya Goeser ◽  
Camille Coates-Clark ◽  
Mark Jenkins
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Impact Damage ◽  
Dynamic Compression ◽  
Dynamic Strain ◽  
Fe Model ◽  
Transverse Impact ◽  
Case Scenario ◽  
Worst Case ◽  
The Impact

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach.

Application of the Mesh Superposition Technique to the Study of Delaminations in Composites Thin Plates

2012 ◽  
Vol 525-526 ◽  
pp. 533-536 ◽  
Author(s):  
Andrea Sellitto ◽  
R. Borrelli ◽  
Francesco Caputo ◽  
Aniello Riccio ◽  
Francesco Scaramuzzino
Keyword(s):  
Composite Structures ◽  
Impact Load ◽  
Laminated Composite ◽  
Low Velocity Impact ◽  
Thin Plates ◽  
Fe Model ◽  
Low Velocity ◽  
Homogenization Approach ◽  
Superposition Technique ◽  
The Impact

Laminated composite structures are increasingly finding more applications in various fields thanks to their lower weight if compared with other materials of the same strength. Nevertheless, composites thin plates show a critical behavior in terms of damage propagation mechanisms when subjected to (low velocity) impact. Indeed they tend to produce delaminations which can be hardly detected by optical inspections and can affect the global load carrying capability, leading to a premature structural collapse. The aim of this paper is to assess the capabilities of the Davies-Zhang approach (introduced in 1994 and aimed to the estimation of both the delamination initiation impact load and the size of the impact induced delaminations) by using a multiscale FE model based on the mesh superposition technique. Indeed the impact area has been modeled layer-wise with an element per layer while the rest of the structure has been modeled at laminate level by layered elements by means of a homogenization approach for the determination of the equivalent laminate material properties. The impact induced delamination area has been determined by adopting stress-based criteria. The results (in terms of delamination initiation impact force and delamination size) have been compared to the ones obtained by adopting the Davies-Zhang approach.

Static Load Distribution and Axial Stiffness in a Planetary Roller Screw Mechanism

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Folly Abevi ◽  
Alain Daidie ◽  
Michel Chaussumier ◽  
Marc Sartor
Keyword(s):  
Load Distribution ◽  
Static Load ◽  
Computing Time ◽  
Three Dimensional ◽  
External Loading ◽  
Axial Stiffness ◽  
Fe Model ◽  
Roller Screw ◽  
Three Dimensional Finite Element ◽  
The Impact

In this paper, an original approach is proposed to calculate the static load distribution and the axial stiffness of a planetary roller screw (PRS) mechanism. Assuming that the external loading is shared equally over an arbitrary number of rollers, only a sector of the system is represented to save on computing time. The approach consists in using a structure of bars, beams, and nonlinear springs to model the different components of the mechanism and their interactions. This nonlinear model describes the details of the mechanism and captures the shape of the nut as well as the bending deformation of the roller. All materials are assumed to operate in the elastic range. The load distribution and the axial stiffness are determined in three specific configurations of the system for both compressive and tensile loads. Further, the influence of the shape of the nut is studied in the case of the inverted PRS. The results obtained from this approach are also compared to those computed with a three-dimensional finite-element (3D FE) model. Finally, since the calculations appear to be very accurate, a parametric study is conducted to show the impact of the bending of the roller on the load distribution.

scholarly journals Impact Response and Damage Characteristics of Carbon Fiber Reinforced Aluminum Laminates Under Low Velocity Impact Loading

2020 ◽  
Vol 9 (4) ◽  
pp. 1831-1837
Keyword(s):  
Impact Energy ◽  
Impact Load ◽  
Three Dimensional ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Low Velocity ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Velocity Impact ◽  
The Impact

CARALL hybrid material has been extensively used in the aircraft structure due to their competitive impact strength. Low velocity impact test is utilized to evaluate the impact and damage properties for such material. It is also employed to observe complex damage mechanisms. A numerical modelling is an alternative way for impact assessment. This paper investigates the impact and damage properties under low velocity impact using numerical modeling and experimental work. A three-dimensional (3D) finite element (FE) model was devolved and validated with two studies from the literature. This model was meshed with solid elements. It was subjected to 2.4 m/s impact velocity and to 10 J impact energy. Absorbed energy, penetration, impact load and damage morphology were obtained. The impact energy was efficiently absorbed by the material. Both aluminum alloy layers underwent plastic deformation whereas the fiber layer failed. A macroscopic cross-sectional morphology was presented using the FE model. An agreement between the numerical and the experiment results were achieved and discussed.

scholarly journals Analysis of Fire Resistance of Square-Cased Square Steel Tube Reinforced Concrete (ST-RC) Columns

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5541
Author(s):  
Gaoxiong Wang ◽  
Yanhong Bao ◽  
Li Yang ◽  
Yang Yu
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Load Ratio ◽  
Internal Force ◽  
Steel Tube ◽  
Fe Model ◽  
Cross Sectional ◽  
Rc Columns

Based on the finite element (FE) analysis software Abaqus, an FE model of square-cased square steel tube reinforced concrete (ST-RC) columns under the hybridized action of high-temperature and load is established. The accuracy of the FE model is verified using experimental data from existing studies. This model is used to analyze the temperature change, internal force distribution, and failure characteristics of the square-cased square ST-RC columns under the action of fire, as well as the factors affecting the fire resistance limit of the column. The results of FE analysis show that under the action of fire, the maximum internal temperature of the square-cased square ST-RC columns occurs in the corner of the section. Moreover, the stress and strain reach their maximum values at the concrete corner outside the tube. During the heating process, an internal force redistribution occurs in the square-cased square ST-RC column. At the same time, the proportion of the axial force and the bending moment of the reinforced concrete outside the pipe decreases gradually, while the proportion of the internal force of the core concrete-filled steel tube (CFST) increases gradually. In essence, it is a process of load transfer from the high-temperature to the low-temperature zone. In addition, the section size, load ratio, slenderness ratio, cross-sectional core area ratio, steel content, and external concrete strength are the main parameters affecting the fire resistance limit of the square-cased square ST-RC columns. Among them, the cross-sectional core area ratio, section size, steel ratio, and external concrete strength are positively correlated with the fire resistance limit of the composite column. On the contrary, with the increase in the load ratio and the slenderness ratio, the fire resistance limit of the square-cased square ST-RC columns decreases. On this basis, a simplified formula to calculate the fire resistance limit of square-cased square ST-RC columns is proposed. The research results can be used as a theoretical reference for the fire protection design of this kind of structure in practical engineering.

scholarly journals Damage Evaluation of the Paving around Manholes under Vehicle Dynamic Load

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Wenjun Hu ◽  
Quanman Zhao ◽  
Yao Liu ◽  
Zhigang Li ◽  
Xianghui Kong
Keyword(s):  
Influencing Factors ◽  
Static Load ◽  
Impact Load ◽  
Fourth Power ◽  
Height Difference ◽  
Driving Speed ◽  
Damage Coefficient ◽  
Longitudinal Slope ◽  
Pavement Damage ◽  
The Impact

It is very important for pavement engineers to know which factors are the main reasons for the damage of the paving around manholes. Based on the investigation on the damage of paving around manholes, a vibration model with multidegree of freedom for the vehicle-manhole cover was established and analyzed. After that, the Matlab software was used to obtain the variation law of impact load over time, and the 95% fourth power of the aggregate force was used as the index to evaluate the pavement damage. Finally, many influencing factors on pavement damage were analyzed by the method of grey correlation entropy. The results indicated that the impact load reached the maximum for the first time when the vehicle reached the top of the manhole cover, which was 1.29 times that of the static load, and the pavement damage coefficient was 2.12 times that of the static load. The influencing factors had different degrees of influence on the pavement damage; from large to small, they were change of road longitudinal slope > driving speed > damping of tire > stiffness of tire > height difference from the pavement damage > height difference from the manhole settlement > stiffness of the manhole cover.

Analysis on Seismic Pounding of Curved Bridge

2011 ◽  
Vol 90-93 ◽  
pp. 800-804
Author(s):  
Qiang Xu ◽  
Xing Jun Qi
Keyword(s):  
Three Dimensional ◽  
Time History ◽  
Bending Moment ◽  
Relative Displacement ◽  
Internal Force ◽  
Curved Bridge ◽  
Reference Base ◽  
History Analysis ◽  
Seismic Pounding ◽  
The Impact

Based on the impact phenomenon between the end of the beam and the bridge abutment of the curved continuous bridge during earthquakes, a spatial finite element calculating model with collision element is presented. The law of collision is studied by the nonlinear contact time history analysis method under two three-dimensional ground motions. The variation laws of relative displacement and the internal force at the bottoms of piers are researched. In addition the changing of displacement and internal force at the end diaphragm are studied. The results show that the pounding action can easily lead to significant collision forces between the end beam and the abutment of the curved bridge which increases the axial force of girder evidently. The collision forces and longitudinal displacements from the inner to outer of the diaphragm generally are showed by an increasing trend, and the pounding action is more fierce under Elcentro ground motion than that under Tianjin ground motion.There is no relative displacement of consolided pier, bending moment and shear force of the consolided pier are greater than that of the mobile pier.The conclusions from the present study may serve as a reference base for seismic design of continuous curved bridges.

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