scholarly journals Simulation of Real Defect Geometry and Its Detection Using Passive Magnetic Inspection (PMI) Method

2018 ◽  
Vol 8 (7) ◽  
pp. 1147 ◽  
Author(s):  
Milad Mosharafi ◽  
SeyedBijan Mahbaz ◽  
Maurice Dusseault
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Time History ◽  
Magnetic Behavior ◽  
Financial Risks ◽  
Reinforcing Steel ◽  
Reinforced Concrete Structure ◽  
Finite Element Software ◽  
History Of

Reinforced concrete is the most commonly used material in urban, road, and industrial structures. Quantifying the condition of the reinforcing steel can help manage the human and financial risks that arise from unexpected reinforced concrete structure functional failure. Also, a quantitative time history of reinforcing steel condition can be used to make decisions on rehabilitation, decommissioning, or replacement. The self-magnetic behavior of ferromagnetic materials is useful for quantitative condition assessment. In this study, a ferromagnetic rebar with artificial defects was scanned by a three-dimensional (3D) laser scanner. The obtained point cloud was imported as a real geometry to a finite element software platform; its self-magnetic behavior was then simulated under the influence of Earth’s magnetic field. The various passive magnetic parameters that can be measured were reviewed for different conditions. Statistical studies showed that 0.76% of the simulation-obtained data of the rebar surface was related to the defect locations. Additionally, acceptable coincidences were confirmed between the magnetic properties from numerical simulation and from experimental outputs, most noticeably at hole locations.

Effect of Finite Rotations on Gyroscopic Sensing Devices

1958 ◽  
Vol 25 (2) ◽  
pp. 210-213
Author(s):  
L. E. Goodman ◽  
A. R. Robinson
Keyword(s):  
Angular Velocity ◽  
Three Dimensional ◽  
Time History ◽  
Simple Method ◽  
Finite Rotations ◽  
Actual Solution ◽  
History Of ◽  
Body Components ◽  
Guidance Systems ◽  
Three Body

Abstract The well-known noncommutativity of three-dimensional finite rotations has long been a curiosity in mechanics since, in actual solution of dynamical problems, the angular velocity, which is conveniently representable as a vector, plays a more natural role. In modern inertial guidance systems, however, the orientation of a body in space, i.e., a rotation, is of primary engineering interest. In this paper a simple method of determining orientation from the time history of three body components of angular velocity is developed by means of a new theorem in kinematics. As a special case of this theorem it is shown that a gyro subjected to a regime of rotations which returns it to the original space orientation will, in general, produce a residual signal. It will have experienced a nonzero and easily calculated mean angular velocity about its input axis. Some implications of the theorem for the design of inertial guidance systems and for the testing of gyros are discussed.

Seismic Analysis and Displacement-Based Evaluation of the Brooklyn-Queens Expressway, New York

2003 ◽  
Vol 1845 (1) ◽  
pp. 213-225
Author(s):  
Robert A. Dameron ◽  
Serafim G. Arzoumanidis ◽  
Steven W. Bennett ◽  
Ayaz Malik
Keyword(s):  
New York ◽  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Nonlinear Models ◽  
Pushover Analysis ◽  
Time History ◽  
Performance Criteria ◽  
Nonlinear Material ◽  
Reinforced Concrete Structure ◽  
Displacement Based

The Brooklyn–Queens Expressway (BQE), Interstate 278 between Atlantic Avenue and Washington Street in Kings County, is an approximately 1,500-m-long multiple-level highway reinforced concrete structure that was built in 1948. It is an important transportation link in the New York City metropolitan area and serves a daily traffic volume of 122,000 vehicles. The longest portion of the BQE consists of elevated one-, two-, and three-level cantilever structures. They are built into the hillside of Brooklyn Heights in successive levels, set back to provide light and air to three lanes of traffic in each direction. They have a unique configuration consisting of rigid frames supporting the roadways with long cantilevers, serving also as retaining walls supporting the hillside beneath adjacent brick buildings. The reinforced concrete portions of the BQE were modeled with finite elements that explicitly represented the concrete and reinforcement and used nonlinear material models. The displacement performance was determined in cyclic pushover analysis that predicted concrete cracking and reinforcing bar yielding. This performance was compared with recently developed displacement performance criteria to establish displacement capacities. The displacement demands were determined by time history analyses using nonlinear models. The methods and criteria that were used for evaluation of the BQE structures are described, and conclusions that may be applicable to future seismic evaluations using the displacement-based approach are provided. Other project challenges are also discussed, including the seismic effects of adjacent buildings and subway tunnels.

Three Dimensional Finite Element Analysis of Reinforced Concrete Rectangular-Sectioned Aqueduct

2013 ◽  
Vol 644 ◽  
pp. 358-361
Author(s):  
Dong Yu Ji
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Element Analysis ◽  
Finite Element Software ◽  
Operating Process ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper adopts general finite element software to carry out three-dimensional finite element simulation analysis for Huizeli reinforced concrete rectangular-sectioned aqueduct. Considering four combination cases in aqueduct’s construction and operating process, researching variation laws of the aqueduct’s stress and displacement. Analysis results show that design scheme of Huizeli reinforced concrete rectangular-sectioned aqueduct is reasonable, it can meet design requirements. Analysis results provide some theory references for design of reinforced concrete rectangular-sectioned aqueduct.

scholarly journals Range of dynamic impact of geotechnical works on reinforced concrete structures

2019 ◽  
Vol 97 ◽  
pp. 03026 ◽  
Author(s):  
Anna Wojtowicz ◽  
Jarosław Michałek ◽  
Andrzej Ubysz
Keyword(s):  
Reinforced Concrete ◽  
Statistical Analysis ◽  
Early Stage ◽  
Relative Displacement ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Reinforced Concrete Structure ◽  
Construction Sites ◽  
Dynamic Impact ◽  
Soil Foundation

Impact of geotechnical works related to plunging piles in the ground and modification of the condition of the soil foundation for concrete in the early stage of its bonding, and influence on adhesion of reinforcing steel to concrete can determinate the target capacity of a reinforced concrete structure. Impact of vibrations testing on bond strength is only possible on real designs or models subjected to dynamic impact. The paper presents mechanisms of adherence reduction caused by relative displacement of reinforcing steel and concrete. Moreover, dynamic influences (frequencies and vibration velocities) measured on structures within and around construction sites, where geotechnical works were carried out were also compared. Data obtained after their statistical analysis might become the basis for modelling an experiment.

scholarly journals Driving Direction Displacement Analysis of Asphalt Pavement under Fluctuating Load

2020 ◽  
Vol 165 ◽  
pp. 03043
Author(s):  
Gao Jianhong ◽  
Xu Youjun ◽  
Yang Shengchun
Keyword(s):  
Dynamic Load ◽  
Transient Analysis ◽  
Asphalt Pavement ◽  
Three Dimensional ◽  
Time History ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Finite Element Software ◽  
Half Wave ◽  
Peak Value

The finite element software ANSYS is used to build the asphalt pavement three-dimensional model and to carry through transient analysis. The z-direction displacement time history curves of asphalt pavement under half wave sine load are obtained. The curves reveal that the dynamic load influence on pavement structure Z-direction displacement is complex; The z-direction displacement always reaches its peak value when the load reaches this point, and it decreases rapidly to zero after the load leaves; The Z-direction displacement influence of dynamic load increases with the increase of depth. These conclusions can provide a reference for asphalt pavement under half wave sinusoidal dynamic load.

Force Analysis of Reinforced Concrete U-Shaped Beam-Supported Aqueduct

2013 ◽  
Vol 394 ◽  
pp. 381-384
Author(s):  
Ke Ding Liu
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Shaped Beam ◽  
Finite Element Software ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Design Requirements ◽  
Three Dimensional Finite Element

This paper adopts general finite element software to carry out three-dimensional finite element simulation analysis for Sunjiagou reinforced concrete U-shaped beam-supported aqueduct. Considering five combination cases in aqueducts construction and operational process, researching variation laws of the aqueducts stress and displacement. Analysis results show that design scheme of Sunjiagou reinforced concrete U-shaped beam-supported aqueduct is reasonable, it can meet design requirements. Analysis results provide some theory references for design of reinforced concrete U-shaped beam-supported aqueduct.

THREE‐DIMENSIONAL GRAVITY INSTABILITY DERIVED FROM TWO‐DIMENSIONAL SOLUTIONS

Geophysics ◽  
1966 ◽  
Vol 31 (1) ◽  
pp. 153-166 ◽  
Author(s):  
M. A. Biot
Keyword(s):  
Three Dimensional ◽  
Time History ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Periodic Patterns ◽  
Numerical Work ◽  
Characteristic Distance ◽  
General Validity ◽  
Dimensional Gravity ◽  
History Of

The theory of three‐dimensional gravity instability of multilayers is developed with particular application to salt structures. It is shown that three‐dimensional solutions are immediately obtained without further numerical work from the solution of the corresponding two‐dimensional problem. Application to a number of typical three‐dimensional structures yields the characteristic distance between peaks and crests and shows that this distance does not differ significantly from the wavelength of the two‐dimensional solution. Various periodic patterns are examined corresponding to rectangular and hexagonal cells. The time history of nonperiodic structures corresponding to initial deviations from perfect horizontality is also derived. The method is applied to the three‐dimensional problem of generation of salt structures when the time‐history of sedimentation is taken into account with variable thickness and compaction of the overburden and establishes the general validity of the geological conclusions derived from the previous two‐dimensional treatment of the same problem (Biot and Odé, 1965). The present method of deriving three‐dimensional solutions, which is developed here in the special context of gravity instability, is valid for a wide variety of problems in theoretical physics.

Parametric Study on the Influence of Bays Number and Frame-Span Length on the Redundancy Indices of Reinforced Concrete Structures

2016 ◽  
Vol 845 ◽  
pp. 259-264
Author(s):  
Mutiara Puspahati Cripstyani ◽  
Stefanus Adi Kristiawan ◽  
Edy Purwanto
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Load Distribution ◽  
Three Dimensional ◽  
Alternative Possibilities ◽  
Span Length ◽  
Reinforced Concrete Structure ◽  
Strength Index ◽  
Capacity Curves ◽  
Variation Index

The role of redundancy in a structure that receives earthquake load is very important. It provides alternative possibilities of load distribution in the event of a local collapse of the system before it reaches the total collapse of the structure. This mechanism of load distribution provides time for the users of the building to escape. A parametric study is carried out to investigate the effect of bays number and frame-span length in order to identify factors affecting the redundancy of the reinforced concrete structural system. Non-linear analysis (pushover) using SAP2000 on three-dimensional structural frames system are performed to obtain the capacity curves of the structures from which redundancies are calculated. Redundancy on the system is determined into two redundancy indices i.e. redundancy strength index (rs) and redundancy variation index (rv) which are, respectively, deterministic and probabilistic measure of the stuctural redundancy. This study points out that frame-span length has more significant effect on redundancy indices compared to the bays number. It is also shown that a reinforced concrete structure with a higher redundancy strength index tends to have a lower redundancy variation index.

scholarly journals Finite Element Analysis on Reinforced Concrete Beams Strengthened with CFRP

2022 ◽  
Vol 2148 (1) ◽  
pp. 012034
Author(s):  
Yihong Hong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structure ◽  
Analysis Model ◽  
Test Beam ◽  
Element Analysis ◽  
Finite Element Software

Abstract Reinforced concrete structure is widely used in building structure because of its unique physical and mechanic properties, but with the increase of service life, there will be different degrees of damage in the structures. In this paper, combined with the test beam, a model of reinforced concrete beam strengthened with CFRP is established by Using ANSYS finite element software, nonlinear finite element analysis is carried out on the whole process of yield, cracking and destruction of the test beam under secondary load, while different working states of CFRP sheets were simulated by the life and death unit. The results show that the bending performance of reinforced concrete (RC) beams strengthened with CFRP can be predicted by selecting the finite element analysis model rationally.

scholarly journals The Effect of Horizontal Vulnerability on the Stiffness Level of Reinforced Concrete Structure on High-Rise Buildings

2020 ◽  
Vol 6 (1) ◽  
pp. 49
Author(s):  
Fanny Monika ◽  
Berkat Cipta Zega ◽  
Hakas Prayuda ◽  
Martyana Dwi Cahyati ◽  
Yanuar Ade Putra
Keyword(s):  
Reinforced Concrete ◽  
Structural Model ◽  
Structural Models ◽  
Time History ◽  
Building Construction ◽  
Reinforced Concrete Structure ◽  
Religious Activities ◽  
Maximum Displacement ◽  
Building Model ◽  
High Rise

Buildings have an essential function; they are a place for people to carry out various activities, such as social, economic, and religious activities. In a building construction plan, considering multiple factors from strength to architecture is necessary. The issue of limited land in some areas has resulted in the construction of vertical buildings, often known as high-rise buildings. High-rise building construction requires paying attention to various levels of vulnerabilities, especially for projects in earthquake-prone areas. In this study, the levels of vulnerability and vertical irregularity of high-rise buildings were analyzed based on structural rigidity for reinforced concrete structures. Building models including a cube-shaped model, L-shaped model, and U-shaped model were investigated. The STERA 3D program was used to determine the strength values of the structures by providing earthquake loads on each structure model using the time-history analysis method. The El Centro and Kobe earthquakes were tested in these structural models because the earthquakes are known to contribute the most exceptional damage value in the history of earthquake-caused disasters. The assessed parameters of the tested structural models include structural stiffness, the most significant displacement in the structure, the maximum displacement and load relations experienced by the construction, and the hysteretic energy exhibited by the structure. Therefore, the best performed structural model in resisting the load could be obtained. The results showed that the U-shaped building model had the highest stiffness value with an increase in stiffness of 7.43% compared with the cube-shaped building model and 3.01% compared with the L-shaped building model.

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