Dynamic Response and Failure Modes of Concrete Slab under Blast Load

2011 ◽  
Vol 94-96 ◽  
pp. 81-85
Author(s):  
Qiao Yan Li ◽  
Gai Hua Yu ◽  
Xiao Yun Guo
Keyword(s):  
Failure Modes ◽  
Concrete Slab ◽  
Dynamic Responses ◽  
Blast Load ◽  
Damage State ◽  
Concrete Material ◽  
Finite Element Program ◽  
Scaled Distance ◽  
Element Program ◽  
The Impact

The impact of blast load is always taken into consideration in significant building and protective construction. In order to study the mechanical behavior of the concrete slab under blast load, the dynamic responses of a square concrete slab under surface explosion are simulated by the nonlinear finite element program ANSYS/LS-DYNA. The JOHNSON_HOLMQUIST_CONCRETE model is used for concrete material and the damage and strain rate effect are considered in this mode1. The simplified exponential load is used as blast load. The Z-displacement,Mises effective stress and damage state of concrete slab under different blast load of corresponding scaled distance are investigated and discussed. It can be found from the results that the influence of blast pressure can be neglected when scaled distance is around 2.0 and the damage of slab is beginning from the edge.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Investigation of Impact of New Design Code on Riser System Design

2009 ◽  
Author(s):  
Alan Yu ◽  
Paul Stanton ◽  
Yongming Cheng
Keyword(s):  
System Design ◽  
Production Systems ◽  
Design Code ◽  
Finite Element Program ◽  
Stress Evaluation ◽  
Element Program ◽  
Steel Catenary Risers ◽  
Ease Of Access ◽  
The Impact ◽  
Gas Lift

Top tensioned risers are fluid conduits from subsea equipment to surface floating production platforms. The advantages of using top tensioned risers are the ability to drill and complete through the production riser, ease of access of the production trees for gas lift operation, and the simplicity of workover and redrill. The integrity of a riser system plays an important role in deepwater developments. Top tensioned risers (TTRs) and steel catenary risers (SCRs) have been widely used with floating production systems such as Spars and TLPs. API RP 2RD [1] has been used to guide riser system design for the last decade. API RP 2RD is being revised as a code (ISO 13628-12) that will also be adopted as a new API code. This paper investigates the impacts of the new design code on the riser system design. This paper first discusses the differences between ISO/WD 13628-12 and the existing API RP 2RD code, particularly the section on design criteria for pipes. The Holstein top tensioned riser system is chosen as an example to evaluate the riser system design impacts. The risers have been installed and successfully producing oil since 2005. The results of the nonlinear finite element program ABAQUS used to analyze the Holstein top tensioned risers were evaluated according to the API RP 2RD. The same analytical results are used for evaluating the impact of the proposed ISO 13628-12 in the area of stress evaluation.

scholarly journals Response of a C-Shaped Building Under Blast Loadings

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1012-1016
Keyword(s):  
Comparative Study ◽  
Research Work ◽  
Blast Load ◽  
Building Structures ◽  
Finite Element Program ◽  
Building Model ◽  
Element Program ◽  
Live Loads ◽  
Triangular Function ◽  
The Comparative Study

Our structures especially building structures, are designed basically for dead loads, live loads for static loading conditions and for wind, earthquake and their combinations for dynamic lateral loadings. As the structures are not designed for unexpected blast load conditions it is not possible for the structures to resist such destructive forces of blast impacts. In this research work a comparative study has been done for the blast forces and earthquake forces. For this study purpose a C-shaped building was modelled for the analysis in finite element program SAP-2000. Initially the building model was analysed for Dead loads, live loads and Earthquake loads. In the second model the building is designed for Blast load. Blast load was defined as a triangular function using codal provisions suggested by IS-4991. The results then are compared and it was checked how far a building designed for EQ can withstand a blast of specific amount of TNT. Also the effect of blast forces due to shape of the building is checked. The comparative study has been mapped and indicated in the paper.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

Predicting the Impact of Quenching on Mechanical Properties of Complex-Shaped Aluminum Alloy Parts

1995 ◽  
Vol 117 (2) ◽  
pp. 479-488 ◽  
Author(s):  
D. D. Hall ◽  
I. Mudawar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Boundary Conditions ◽  
Finite Element Program ◽  
Part Geometry ◽  
Heat Treated ◽  
Element Program ◽  
Nozzle Configuration ◽  
The Impact

The mechanical properties of age-hardenable aluminum alloy extrusions are critically dependent on the rate at which the part is cooled (quenched) after the forming operation. The present study continues the development of an intelligent spray quenching system, which selects the optimal nozzle configuration based on part geometry and composition such that the magnitude and uniformity of hardness (or yield strength) is maximized while residual stresses are minimized. The quenching of a complex-shaped part with multiple, overlapping sprays was successfully modeled using spray heat transfer correlations as boundary conditions within a finite element program. The hardness distribution of the heat-treated part was accurately predicted using the quench factor technique; that is, the metallurgical transformations that occur within the part were linked to the cooling history predicted by the finite element program. This study represents the first successful attempt at systematically predicting the mechanical properties of a quenched metallic part from knowledge of only the spray boundary conditions.

THE EFFECT OF IMPACT LOADS ON PRESTRESSED CONCRETE SLABS

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Youmn Al Rawi ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Mohamad Elani
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Reinforced Concrete Slab ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
The Impact

Many research studies have been conducted on the effect of impact loading on structures, and design procedures were proposed for reinforced concrete (RC) slabs; however the availability of these studies and procedures are limited for prestressed slabs. The proposed research will examine, using numerical analysis, the impact of rock fall on prestressed concrete slabs with equivalent moment capacity reinforced concrete slabs. It is expected that prestressed concrete slabs will have different behavior to resist impact loading compared with traditional reinforced concrete slabs. The thickness of the prestressed concrete slab will be 25cm whereas that of the reinforced concrete slab will be 30cm. The impact loading consists of 500Kg drop weight. The drop height will be 10m, 15m and 20m.The structural analysis is performed using a Finite Element program "ABAQUS". A comparison will be done between both slab types in terms of failure mode, damage, and deflection. It has been found that both slabs failed in punching. However, the RC slab performed better than the prestressed concrete slab with respect to the value of the deflection at mid-span, while both showed punching shear mode of failure.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

Analysis on Axial Compression Ratio to Strong Column Weak Beam Effect in Framework Node

2014 ◽  
Vol 578-579 ◽  
pp. 16-19
Author(s):  
Xin Wen ◽  
Ze Jing Hao ◽  
Xing Guo Wang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Pressure Ratio ◽  
Finite Element Program ◽  
Static State ◽  
Axial Compression Ratio ◽  
Weak Beam ◽  
Element Program ◽  
The Impact

Nodes of Column ends, included ordinary Intermediate nodes and nodes in the model of carbon fiber, have been established based on finite element program, have analyzed the comparison of the deformation, bearing capacity, ductility in Quasi static state under three conditions of axial compression ratio reinforcement (0.2, 0.4, 0.6) between reinforcement nodes and ordinary nodes, have researched the impact caused by the change of axial pressure ratio on seismic performance of node, The result have shown that size of the axial compression ratio and bearing capacity of reinforced nodes follow basic plastics performance, but ductility of nodes in low axial compression ratio is more effective.

scholarly journals Experimental Investigation of Impact Response of RC Slabs with a Sandy Soil Cushion Layer

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jianli Wu ◽  
Guotao Ma ◽  
Zhenhua Zhou ◽  
Xuefeng Mei ◽  
Xiewen Hu
Keyword(s):  
Layer Thickness ◽  
Sandy Soil ◽  
Failure Modes ◽  
Impact Force ◽  
Concrete Slab ◽  
Failure Process ◽  
Impact Response ◽  
Rc Slabs ◽  
Cushion Layer ◽  
The Impact

The impact response of reinforced-concrete (RC) slabs covered with a sandy soil cushion layer was investigated using an outdoor rockfall impact test platform. Impact tests were carried out by releasing rockfalls with different weights from different heights to impact a combined structure. Test data included the acceleration duration curve of the rockfall, strain of the concrete slab at multiple measuring points, and midpoint displacement duration curve of the slab. The test results showed an exponential relationship between the impact force acting on the cushion layer surface and cushion layer thickness. An empirical formula was used to calculate the maximum penetration, and the result was in good agreement with the test value. In addition, the attenuation rate of the impact force acting on the cushion layer increased exponentially with the increase in the cushion layer thickness, and the peak impact force could be attenuated by approximately 70% at a thickness of 0.6 m. Finally, the failure process and failure modes of the RC slabs were investigated.

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