New proposed drift limit states for box-type structural systems considering local and global damage indices

2019 ◽  
Vol 22 (15) ◽  
pp. 3352-3366 ◽  
Author(s):  
Vahid Mohsenian ◽  
Alireza Mortezaei
Keyword(s):  
Damage Index ◽  
Three Dimensional ◽  
Local Damage ◽  
Structural System ◽  
Limit States ◽  
Maximum Displacement ◽  
Damage Indices ◽  
Expected Performance ◽  
Immediate Occupancy ◽  
Drift Limit

The maximum displacement responses under the seismic motions are usually considered as an indicator for damage evaluation. It is obvious that appropriate selection of drifts corresponding to various damage levels plays an important role in safety and economy of a design project. Despite the extensive use of the box-type structural system in mass construction and housing industry, there is no special design requirement for this structural system. Due to three-dimensional behavior and interaction of intersecting walls and slabs, it is expected that this system presents different seismic performance in comparison to the conventional shear wall buildings. This study evaluates the overall and story failure mechanism as well as global and local damage indices in this structural system. Maximum allowable drift ratios of 0.45%, 0.65%, and 0.8% are suggested for the immediate occupancy, life safety, and collapse prevention levels, respectively. Moreover, a damage index based on the maximum relative inter-story drifts is proposed to assess the failure in the height domain. According to the assessments, the story and global failure occurring due to considerable damages in main load bearing elements reveals high importance of local damage indices in box-type structural system. Based on the results, it is concluded that the proposed maximum values for drifts in different standards and codes are not reliable. Considering the shear-control behavior and depending on the expected performance levels, the proposed local damage indices are considered as accurate control indicators for box-type structural system.

scholarly journals Local Damage Indices of Frames Consisting of Composite Beams and RC Columns

2016 ◽  
Vol 10 (1) ◽  
pp. 280-292
Author(s):  
Wei Li ◽  
Linzhu Sun ◽  
Kejia Yang ◽  
Lei Wang ◽  
Dongyan Wu ◽  
...  
Keyword(s):  
Composite Structures ◽  
Damage Model ◽  
Damage Index ◽  
High Strength ◽  
Steel Beams ◽  
Local Damage ◽  
Composite Frame ◽  
Damage Indices ◽  
Study Results ◽  
Scope Of Application

The study is to propose the local damage indices of composite frame structures consisting of high-strength concrete columns confined by continuous compound spiral ties and steel beams (CCSTRCS), the local damage indices would lay a foundation for the study of the overall damage indices for composite CCSTRCS frame. The Mehanny damage model has been modified to predict the local damage behavior of composite CCSTRCS frames, it enlarges the scope of application for the composite structures compared with the previous work. The proposed model is validated by comparing with the present references. The study results suggest the different components corresponding to the extent of the damage and its damage index.

Practitioner-friendly design method to improve the seismic performance of RC frame buildings

2021 ◽  
pp. 875529302098801
Author(s):  
Orlando Arroyo ◽  
Abbie Liel ◽  
Sergio Gutiérrez
Keyword(s):  
Seismic Performance ◽  
Design Method ◽  
Three Dimensional ◽  
Rc Frame ◽  
Structural System ◽  
Standard Code ◽  
Frame Buildings ◽  
Rc Frame Buildings ◽  
Mathematical Justification ◽  
Story Building

Reinforced concrete (RC) frame buildings are a widely used structural system around the world. These buildings are customarily designed through standard code-based procedures, which are well-suited to the workflow of design offices. However, these procedures typically do not aim for or achieve seismic performance higher than code minimum objectives. This article proposes a practical design method that improves the seismic performance of bare RC frame buildings, using only information available from elastic structural analysis conducted in standard code-based design. Four buildings were designed using the proposed method and the prescriptive approach of design codes, and their seismic performance is evaluated using three-dimensional nonlinear (fiber) models. The findings show that the seismic performance is improved with the proposed method, with reductions in the collapse fragility, higher deformation capacity, and greater overstrength. Furthermore, an economic analysis for a six-story building shows that these improvements come with only a 2% increase in the material bill, suggesting that the proposed method is compatible with current project budgets as well as design workflow. The authors also provide mathematical justification of the method.

Inelastic Limit States Design Part II: Three‐Dimensional Frame Study

1992 ◽  
Vol 118 (9) ◽  
pp. 2550-2568 ◽  
Author(s):  
Ronald D. Ziemian ◽  
William McGuire ◽  
Gregory G. Dierlein
Keyword(s):  
Three Dimensional ◽  
Limit States

The Influence of Needle Eccentric Motion On Hole-to-Hole Injection Characteristics of a Two-Layered 8-Hole Diesel Injector

2021 ◽  
Author(s):  
Tianyu Jin ◽  
Yu Sun ◽  
Chuqiao Wang ◽  
Adams Moro ◽  
Xiwen Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Injection Rate ◽  
Hole Injection ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
Fuel Flow ◽  
Diesel Injection ◽  
Eccentric Motion

Abstract The stringent emission regulations diesel engines are required to meet has resulted in the usage of multi-hole and ultra-multi-hole injectors, nowadays. In this research study, a double layered 8-hole diesel injection nozzle was investigated both numerically and experimentally. A three-dimensional model of the nozzle which was validated with experimental results was used to analyze the injection characteristics of each hole. The validation was conducted by comparing experiment and simulation injection rate results, acquired simultaneously from all the holes of the injector and the model. The fuel flow rates of the lower layered holes are higher than those of the upper layered holes. Two different needle eccentricity models were established. The first model only included the lateral displacement of the needle during needle lift. The needle reached maximum displacement at full needle lift. The second model considered the needle inelastic deformation into consideration. The needle radially displaces and glides along with the needle seat surface during needle lift. When the eccentricity reached maximum in the radial direction, the needle began to lift upwards vertically. The differences in injection characteristics under the different eccentricity models were apparent. The results indicated that the cycle injection quantity, fuel injection rate and cavitation of each hole were affected during the initial lifting stages of the needle lift. As the eccentricity of the needle increases, the injection rate uniformity from the nozzle hole deteriorates. The result showed that the upper layered holes were affected by the needle eccentricity during needle lift.

scholarly journals Hybrid backpropagation neural network-particle swarm optimization for seismic damage building prediction

2019 ◽  
Vol 14 (1) ◽  
pp. 360
Author(s):  
Marina Yusoff ◽  
Faris Mohd Najib ◽  
Rozaina Ismail
Keyword(s):  
Neural Network ◽  
Particle Swarm Optimization ◽  
Damage Index ◽  
Particle Swarm ◽  
Seismic Damage ◽  
Backpropagation Neural Network ◽  
Swarm Optimization ◽  
Local Optima ◽  
Damage Indices ◽  
Prediction Problems

The evaluation of the vulnerability of buildings to earthquakes is of prime importance to ensure a good plan can be generated for the disaster preparedness to civilians. Most of the attempts are directed in calculating the damage index of buildings to determine and predict the vulnerability to certain scales of earthquakes. Most of the solutions used are traditional methods which are time consuming and complex. Some of initiatives have proven that the artificial neural network methods have the potential in solving earthquakes prediction problems. However, these methods have limitations in terms of suffering from local optima, premature convergence and overfitting. To overcome this challenging issue, this paper introduces a new solution to the prediction on the seismic damage index of buildings with the application of hybrid back propagation neural network and particle swarm optimization (BPNN-PSO) method. The prediction was based on damage indices of 35 buildings around Malaysia. The BPNN-PSO demonstrated a better result of 89% accuracy compared to the traditional backpropagation neural network with only 84%. The capability of PSO supports fast convergence method has shown good effort to improve the processing time and accuracy of the results.

scholarly journals Deformation Characteristics of the Surrounding Rock of a Six-Lane Multiarch Tunnel under Different Excavation Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lina Luo ◽  
Gang Lei ◽  
Haibo Hu
Keyword(s):  
Three Dimensional ◽  
Class Ii ◽  
Surrounding Rock ◽  
Displacement Rate ◽  
Construction Technology ◽  
Deformation Characteristics ◽  
Highway Traffic ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Secondary Lining

Highway tunnel plays an increasingly prominent role in the development of high-grade highway traffic in mountainous countries or regions. Therefore, it is necessary to explore the deformation characteristics of the surrounding rock of a six-lane multiarch tunnel under different excavation conditions. Using the three-dimensional indoor model test and finite element analysis, this paper studies the dynamic mechanical behavior of a six-lane construction, reveals the whole process of the surrounding rock deformation process of class II surrounding rock under different excavation conditions, and puts forward the best construction and excavation method. The results show that the maximum displacement rate of excavation scheme III is the largest, and the maximum displacement rate of excavation scheme I is basically the same as that of excavation scheme II. Therefore, in terms of controlling the displacement rate of the surrounding rock, the effect of excavation scheme I is basically the same as that of excavation scheme II, while that of excavation scheme III is poor. In terms of construction technology, scheme II is simpler than scheme I and can ensure the integrity of the secondary lining. Therefore, in class II surrounding rock of the supporting project, it is recommended to adopt scheme II for construction.

scholarly journals Evaluation of Damage Indices for Rectangular Concrete-filled Steel Tube Structures

2019 ◽  
Vol 19 (4) ◽  
pp. 170-184
Author(s):  
Minsheng Guan ◽  
Siying Lin ◽  
Hongbiao Du ◽  
Jie Cui ◽  
Taizhou Yan
Keyword(s):  
Comprehensive Evaluation ◽  
Selection Process ◽  
Slenderness Ratio ◽  
Damage Index ◽  
Steel Tube ◽  
Stiffness Ratio ◽  
Concrete Filled Steel Tube ◽  
Damage Indices ◽  
Drift Ratio ◽  
Secant Stiffness

Abstract The paper aims to select a simple and effective damage index for estimating the extent of damage of rectangular concrete-filled steel tube (RCFT) structures subjected to ground motions. Two experimental databases of cyclic tests conducted on RCFT columns and frames are compiled. Test results from the database are then used to evaluate six different damage indices, including the ductility ratio (μ), drift ratio, initial-to-secant stiffness ratio (DKJ), modified initial-to-secant stiffness ratio (Dms), energy coefficient (E), and the combined damage index (DPA) as a benchmark indicator. Selection criteria including correlation, efficiency, and proficiency are utilized in the selection process. The optimal alternative for DPA is identified on the basis of a comprehensive evaluation. The evaluations indicate that Dms previously proposed by some of the authors is the most appropriate substitution of DPA, followed by the drift ratio. For the case of the slenderness ratio less than or equal to 30, the same grades of relation between the investigated damage indices and the benchmark are observed. However, in the case of the slenderness ratio larger than 30, the drift ratio tends to be the optimal alternative. In most cases, μ is proved to be an inadequate replacement of DPA.

scholarly journals Kinematics of the Lumbo–Pelvic Complex under Different Loading Conditions

2019 ◽  
Vol 5 (1) ◽  
pp. 347-349
Author(s):  
Martin Weidling ◽  
Christian Voigt ◽  
Toni Wendler ◽  
Martin Heilemann ◽  
Michael Werner ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Axial Rotation ◽  
Image Correlation ◽  
Loading Conditions ◽  
Structural System ◽  
Lateral Bending ◽  
Test Rig ◽  
Hip Joints ◽  
Complex Structural ◽  
The Right

AbstractThe lumbo-pelvic complex is a highly complex structural system. The current investigation aims to identify the kinematics between interacting bone segments under different loading conditions. A specimen of the lumbo-pelvic complex was obtained from a human body donor and tested in a self-developed test rig. The experimental setup was designed to imitate extension, flexion, right and left lateral bending and axial rotation to the left and to the right, respectively. The vertebra L3 was firmly embedded and load was introduced via hip joints. Using a digital image correlation (DIC) system, the 3D motions of 15 markers at different landmarks were measured for each loadcase under cyclic loading. For each loadcase, the kinematics were analyzed in terms of three-dimensional relative movements between L3 and the sacrum. The usefulness of the experimental technique was demonstrated. It may serve for further biomechanical investigations of relative motion of sacroiliac and vertebral joints and deformation of bony structures.

scholarly journals Safety Evaluation of Underground Caverns Based on Monte Carlo Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qifeng Guo ◽  
Zhihong Dong ◽  
Meifeng Cai ◽  
Fenhua Ren ◽  
Jiliang Pan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Cumulative Distribution ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
The Monte Carlo Method ◽  
Underground Caverns ◽  
The Stability

In order to study the influence of joint fissures and rock parameters with random characteristics on the safety of underground caverns, several parameters affecting the stability of surrounding rock of underground caverns are selected. According to the Monte Carlo method, random numbers satisfying normal distribution characteristics are established. A three-dimensional model of underground caverns with random characteristics is established by discontinuous analysis software 3DEC and excavation simulations are carried out. The maximum displacement at the numerical monitoring points of arch and floor is the safety evaluation index of the cavern. The probability distribution and cumulative distribution function of the displacement at the top arch and floor are obtained, and the safety of a project is evaluated.

Planning 3D Well Trajectories Using Cubic Functions

2006 ◽  
Vol 128 (4) ◽  
pp. 257-267 ◽  
Author(s):  
Jorge H. B. Sampaio
Keyword(s):  
Three Dimensional ◽  
Continuous Functions ◽  
Gradual Change ◽  
Average Curvature ◽  
Expected Performance ◽  
End Conditions ◽  
Planning Cycle ◽  
Path Curvature ◽  
Lower Torque ◽  
Equipment Wear

This work presents a mathematical method to design complex trajectories for three-dimensional (3D) wells. Three-dimensional cubic trajectories are obtained for various end conditions: free end, set end, free inclination/set azimuth, and set inclination/free azimuth. The resulting trajectories are smooth continuous functions, which better suit the expected performance of modern rotary steerable deviation tools, in particular point-the-bit and push-the-bit systems. A continuous and gradual change in path curvature and tool face results in the smoothest trajectory for 3D wells, that in turn results in lower torque, drag, and equipment wear. The degree of freedom and the associated parameters of the 3D curves express the commitment between the average curvature to the final length of the path, which can be adjusted to fit the design requirements and to optimize the trajectory. Several numerical examples illustrate the various end conditions. The paper also presents the full mathematical results (expressions for the 3D path, actual curvature, and actual tool face). The method is directly applicable to the well planning cycle as well as to automatic and manual hole steering.

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