scholarly journals Improving Blast Performance of Reinforced Concrete Panels Using Sacrificial Cladding with Hybrid-Multi Cell Tubes

Modelling ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 149-165
Author(s):  
Mahmoud Abada ◽  
Ahmed Ibrahim ◽  
S.J. Jung
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Plate Thickness ◽  
Core Layer ◽  
Engineering Structures ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Thin Walled ◽  
The Impact

The utilization of sacrificial layers to strengthen civilian structures against terrorist attacks is of great interest to engineering experts in structural retrofitting. The sacrificial cladding structures are designed to be attached to the façade of structures to absorb the impact of the explosion through the facing plate and the core layer progressive plastic deformation. Therefore, blast load striking the non-sacrificial structure could be attenuated. The idea of this study is to construct a sacrificial cladding structure from multicellular hybrid tubes to protect the prominent bearing members of civil engineering structures from blast hazard. The hybrid multi-cell tubes utilized in this study were out of staking composite layers (CFRP) around thin-walled tubes; single, double, and quadruple (AL) thin-walled tubes formed a hybrid single cell tube (H-SCT), a hybrid double cell tube (H-DCT), and a hybrid quadruple cell tube (H-QCT). An unprotected reinforced concrete (RC) panel under the impact of close-range free air blast detonation was selected to highlight the effectiveness of fortifying structural elements with sacrificial cladding layers. To investigate the proposed problem, Eulerian–Lagrangian coupled analyses were conducted using the explicit finite element program (Autodyn/ANSYS). The numerical models’ accuracy was validated with available blast testing data reported in the literature. Numerical simulations showed a decent agreement with the field blast test. The proposed cladding structures with different core topologies were applied to the unprotected RC slabs as an effective technique for blast loading mitigation. Mid-span deflection and damage patterns of the RC panels were used to evaluate the blast behavior of the structures. Cladding structure achieved a desired protection for the RC panel as the mid-span deflection decreased by 62%, 78%, and 87% for H-SCT, H-DCT, and H-QCT cores, respectively, compared to the unprotected panels. Additionally, the influence of the skin plate thickness on the behavior of the cladding structure was investigated.

scholarly journals Common irregularities and its effects on reinforced concrete building response

2021 ◽  
Vol 17 (1) ◽  
pp. 63-73
Author(s):  
Krishna Ghimire ◽  
Hemchandra Chaulagain
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Numerical Models ◽  
Time History ◽  
Functional Requirements ◽  
Finite Element Program ◽  
Reinforced Concrete Building ◽  
Concrete Building ◽  
Element Program ◽  
Dynamic Time

In most of the countries, the irregular building construction is popular for fulfilling both aesthetic and functional requirements. However, the evidence of past earthquakes in Nepal and the globe demonstrated the higher level of seismic vulnerability of the buildings due to irregularities. Considering this fact, the present study highlighted the common irregularities and its effect on reinforced concrete building response. The effect of structural irregularities was studied through numerical analysis. The geometrical, mass and stiffness irregularities were created by removing bays in different floor levels and removing the columns at different sections respectively. In this study, the numerical models were created in finite element program SAP2000. The structural performance was studied using both non-linear static pushover and dynamic time history analysis. The results indicate that the level of irregularities significantly influenced the behavior of structures.

Reliability Analysis of Reinforced Concrete (RC) Plates and Shells

2012 ◽  
Author(s):  
Pattabhi Sitaram ◽  
Sudhir Kaul
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Reliability Analysis ◽  
Design Parameters ◽  
Design Codes ◽  
Engineering Structures ◽  
Finite Element Program ◽  
Holistic Understanding ◽  
Element Program ◽  
Plates And Shells

The application of the principles of probabilistic techniques to structural design has been gaining widespread acceptance over the last two decades. However, the design of many engineering structures is still based on standard deterministic design codes that may not account for inherent design and material variability. Although design codes have been successfully used for many decades, the use of probabilistic design allows a designer to get a more holistic understanding of design variables and a clear assessment of uncertainties. This paper evaluates the reliability of plates and shells made from reinforced concrete (RC) that are commonly used in engineering structures. A modified Monte Carlo approach is used to capture variability in design parameters such as the spacing of the reinforcement, the diameter of the reinforcement and material thickness of the concrete as well as material properties of concrete. The ultimate load carrying capacity is used as the primary failure mode for reliability analysis and the onset of cracking and deflection are also monitored for all the runs that are made for computing reliability. A nonlinear finite element program is used for analysis and the results from the finite element program are used for computing reliability. A sensitivity analysis is performed to determine the most significant parameters influencing the reliability of plates and shells used in this study.

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.

scholarly journals Numerical Derivation of Iso-Damaged Curve for a Reinforced Concrete Beam Subjected to Blast Loading

2018 ◽  
Vol 149 ◽  
pp. 02016 ◽  
Author(s):  
Yehya Temsah ◽  
Ali Jahami ◽  
Jamal Khatib ◽  
M Sonebi
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shock Waves ◽  
Concrete Beam ◽  
Blast Loading ◽  
Reinforced Concrete Beam ◽  
Structural Elements ◽  
Finite Element Program ◽  
Element Program ◽  
Structural Engineers

Many engineering facilities are severely damaged by blast loading. Therefore, many manufacturers of sensitive, breakable, and deformed structures (such as facades of glass buildings) carry out studies and set standards for these installations to withstand shock waves caused by explosions. Structural engineers also use these standards in their designs for various structural elements by following the ISO Damage Carve, which links pressure and Impulse. As all the points below this curve means that the structure is safe and will not exceed the degree of damage based on the various assumptions made. This research aims to derive the Iso-Damage curve of a reinforced concrete beam exposed to blast wave. An advanced volumetric finite element program (ABAQUS) will be used to perform the derivation.

Passive Safety Analysis for the Commercial Vehicle Cab after Weight-Reduction Design

2015 ◽  
Vol 798 ◽  
pp. 48-52 ◽  
Author(s):  
Jing Chen ◽  
Hong Yin Wang ◽  
Qian Wang ◽  
Xiong Long Tao
Keyword(s):  
Weight Reduction ◽  
Strength Test ◽  
Commercial Vehicles ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Wall Strength ◽  
Element Program ◽  
Roof Strength ◽  
Front Impact ◽  
Crash Tests

Lighter weight commercial vehicles facilitate faster transport, higher mobility and fuel conservation. Weight reduction and safety are mutually competing objectives. And the safety should not be compromised after weight reduction. Full size crash tests are expensive and time consuming to organize. Using a numerical simulation for predicting crash to the occupants’ safety can minimize the number of such trials. In this paper three virtual crash simulations for the three load cases: Front impact test, Roof strength test and Rear wall strength test are performed according to the European regulation ECE-R29. The explicit finite element program LS-DYNA is used for that purpose. The comparisons between simulation results and test data available in the literature are also presented in this paper.

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 TECHNOLOGY OF COMPUTATION OF REINFORCED CONCRETE STRUCTURES/GELŽBETONINŲ KONSTRUKCIJŲ ARMATŪROS AUTOMATIZUOTO SKAIČIAVIMO TECHNOLOGIJA

2001 ◽  
Vol 7 (6) ◽  
pp. 419-424
Author(s):  
Arvydas Jurkša
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
New Technology ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Finite Element Program ◽  
Code Of Practice ◽  
Element Program

The author has created a new technology for concrete beam, column, slab, wall and shell reinforcement computation according to the finite element program COSMOS/M analysis results and code of practice valid in Lithuania. A brief description of the technology is included in the article. Computer programmes COSARM and COSMAX were designed for slab, wall and shell reinforcement computation. Results can be visualized graphically. New computer programmes BEAM, COSBEAM, COLUMN, COSREC and COSCIR were created for beam and column reinforcement computation. The new technology extremely enlarged the possibilities of the powerful finite element program COSMOS/M and enabled to compute very complicated reinforced concrete structures.

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.

Virtual Testing for Frontal Impact of High-Top Cab of Heavy Truck

2011 ◽  
Vol 148-149 ◽  
pp. 1081-1084
Author(s):  
Wei Wang ◽  
Xu Liang Xie ◽  
Fu Lin Shen ◽  
Xiao Feng Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Front Seat ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Commercial Code ◽  
Element Program ◽  
Heavy Truck ◽  
Survival Space ◽  
Pendulum Impact

ECE R29 regulation has legally claimed that the survival space must be guaranteed for the safety for driver and front seat passenger in event of crash during design of truck cabin. In this paper, a finite element model of a high-top cabin of a heavy truck with a manikin on the driver seat was built with commercial code Hypermesh, The explicit finite element program Ls-Dyna was used to simulate the frontal pendulum impact on the high-top cab in the light of ECE R29 regulation. Deformation of the truck cabin and the survival space of the dummy were analyzed and discussed. Also, some suggestions were given to solve the contact possibility between steering column and the knees of manikin.

Spalling in Continuously Reinforced Concrete Pavement in Texas

2020 ◽  
Vol 2674 (11) ◽  
pp. 731-740
Author(s):  
Pangil Choi ◽  
Lochana Poudyal ◽  
Fouzieh Rouzmehr ◽  
Moon Won
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Coefficient Of Thermal Expansion ◽  
Field Testing ◽  
Concrete Pavement ◽  
Materials Testing ◽  
Finite Element Program ◽  
Texas Department ◽  
Conducting Materials ◽  
Element Program

The performance of continuously reinforced concrete pavement (CRCP) in Texas has been quite satisfactory, primarily thanks to the continuous improvements in design and construction. However, severe spalling has been a major problem, and the Texas Department of Transportation (TxDOT) has sponsored several research projects since 1985 to identify solutions for this serious problem. Even though the research efforts were successful in identifying spalling mechanisms, developing a policy that TxDOT could easily implement has been a challenge. To develop a more practical solution to this problem, TxDOT initiated a research study, and the research efforts consisting of identifying CRCP projects with severe and no spalling, obtaining and conducting materials testing on concrete cores from those projects, analyzing the testing data, and performing theoretical analyses to validate the testing results. Among the material properties evaluated, the coefficient of thermal expansion (CTE) of concrete proved to have the best correlation with spalling. Detailed analyses of mechanistic behavior of concrete conducted with an object-oriented finite element program (OOF2) and commercial finite element program verified the reasonableness of the field-testing results. All concrete cores from CRCP with severe spalling had a CTE larger than 5.5 microstrains/°F, whereas no spalling was observed in concrete with a CTE less than that value. Based on this finding, TxDOT now requires the use of coarse aggregate that will produce concrete with a CTE of less than 5.5 microstrains/°F for CRCP construction. It is expected that this implementation will reduce the spalling in CRCP substantially.

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