scholarly journals Evaluation of Failure Probability in Series System of Three-Axle Trucks under Strong Crosswind

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yahui Hu ◽  
Yingshi Guo ◽  
Rui Fu ◽  
Qingjin Xu
Keyword(s):  
Failure Probability ◽  
Lateral Displacement ◽  
Center Of Mass ◽  
Time History ◽  
General Information ◽  
Time Varying ◽  
Series System ◽  
Road Transportation ◽  
Force Coefficient ◽  
Average Wind Speed

The probability of wind-induced failure accidents in three-axle trucks under pulsating strong crosswinds and the corresponding critical safe speed are investigated in this study. Reliability theory and random fuzzy methods are utilized to establish the membership function of the failure probability in the series system (FPSS) composed of rollover, side-slip, and rotation failure accidents. The Kaman spectrum is used to realistically simulate the fluctuating wind time history curves of different average speeds. Four factors affecting the six-component force coefficient of the three-axle truck and the crosswind load are considered: fluctuating average wind speed, wind direction (angle), truck driving speed, and road adhesion coefficient. A three-axle truck nonlinear model is established accordingly. The model is used to obtain the dynamic response of the three-axle truck under strong crosswind conditions as per the time-varying curves of the vertical load of the truck, the time-varying curves of the lateral displacement of the center of mass, and the time-varying curves of the heading angle. An advanced Monte Carlo simulation algorithm based on importance sampling is used to determine the probability of a three-axle truck with FPSS under strong crosswinds; the given acceptable probability of failure (accident) is used to obtain the critical safety speed. The sensitivity analysis of random variables reveals that the possibility of three truck failures of the three-axle truck in strong crosswinds is, from largest to smallest, rollover, side-slip, and rotation. This research may provide useful guidance for exploring the probability of wind-induced accidents and the critical safety speeds of vehicles, as well as useful general information for road transportation management departments.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

Inverse estimation of time-varying heat transfer coefficients for a hollow cylinder by using self-learning particle swarm optimization

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kun-Yung Chen ◽  
Te-Wen Tu
Keyword(s):  
Heat Transfer ◽  
Particle Swarm Optimization ◽  
Objective Function ◽  
Hollow Cylinder ◽  
General Type ◽  
Particle Swarm ◽  
Time History ◽  
Time Varying ◽  
Swarm Optimization ◽  
Self Learning

Abstract An inverse methodology is proposed to estimate a time-varying heat transfer coefficient (HTC) for a hollow cylinder with time-dependent boundary conditions of different kinds on inner and outer surfaces. The temperatures at both the inner surface and the interior domain are measured for the hollow cylinder, while the time history of HTC of the outer surface will be inversely determined. This work first expressed the unknown function of HTC in a general form with unknown coefficients, and then regarded these unknown coefficients as the estimated parameters which can be randomly searched and found by the self-learning particle swarm optimization (SLPSO) method. The objective function which wants to be minimized was found with the absolute errors between the measured and estimated temperatures at several measurement times. If the objective function converges toward the null, the inverse solution of the estimated HTC will be found eventually. From numerical experiments, when the function of HTC with exponential type is performed, the unknown coefficients of the HTC function can be accurately estimated. On the contrary, when the function of HTC with a general type is conducted, the unknown coefficients of HTC are poorly estimated. However, the estimated coefficients of an HTC function with the general type can be regarded as the equivalent coefficients for the real function of HTC.

A Study on the Restrainer for Isolated Bridge

2011 ◽  
Vol 243-249 ◽  
pp. 5208-5213
Author(s):  
Yong Feng Du ◽  
Xiao Yu Sun
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Nonlinear Characteristics ◽  
Isolation System ◽  
Finite Element Software ◽  
Continuous Beam Bridge ◽  
History Analysis ◽  
Isolated Bridge ◽  
Isolated Bridges ◽  
Beam Bridge

As a result of adopting isolated bearings, it is inevitable to increase the lateral displacement of the superstructure and the chance of girder falling. However, the shear keys that just satisfies the structural design is far from meeting the requirements of displacement of isolated bridge restrictions. On account of this, given the nonlinear characteristics of bearings and the restrainer, the authors make the study on the "damping rubber with coupling collar" restrainer, and then establish isolation system model of continuous beam bridge with finite element software named Midas. Meanwhile, the effect of the restrainer on the dynamic response of isolated bridges is presented by time-history analysis, which reveals the great value in the application of limiting displacement of isolated bridge.

scholarly journals Nonlinear Dynamic Identification of Beams Resting on Nonlinear Viscoelastic Foundations Based on the Time-Delayed Transfer Entropy and Improved Surrogate Data Algorithm

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Guohua Liu ◽  
Changpeng Ye ◽  
Xu Liang ◽  
Zhongkai Xie ◽  
Ziyuan Yu
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Original Data ◽  
Surrogate Data ◽  
Transfer Entropy ◽  
Dynamic Identification ◽  
Concentrated Load ◽  
Nonlinear Foundation ◽  
Young’S Moduli ◽  
The Galerkin Method

In this work, the transfer entropy and surrogate data algorithm were introduced to identify the nonlinearity level of the system by using a numerical solution of nonlinear response of beams. A homogeneous Euler-Bernoulli beam was subjected to a time-varying concentrated load and resting on a nonlinear foundation. The Galerkin method was applied to discretize the dimensionless differential governing equation of the forced vibration, and then the fourth-order Runge-Kutta method was used to obtain the time-history response of the lateral displacement. In order to simulate different nonlinearity levels, different ratios between nonlinear parameters and linear parameters of foundation, as well as different Young’s moduli, were used. A nonlinearity index was proposed. In the case of different nonlinearity levels, the nonlinearity index was used to analyze the difference between the transfer entropy calculated from the original data and the transfer entropy calculated from the surrogate data. By comparing and analyzing the nonlinearity index values under different ratios, it was found that the nonlinearity index values generally increased with the increase of the ratio and the sum of nonlinearity index values had a positive correlation with the ratio. By comparing the nonlinearity index values of the transfer entropy results of beams with different Young's moduli, it was found that the sum of the nonlinearity index values generally decreased with the increase of Young's modulus. The numerical results demonstrate that the present approach could effectively quantify the nonlinearity in the response of a beam resting on a nonlinear foundation.

scholarly journals Review on Seismic Analysis of Multistoried Building in Hilly Region

2021 ◽  
Vol 9 (12) ◽  
pp. 73-79
Author(s):  
Harsh Joshi
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Center Of Mass ◽  
Time History ◽  
Lateral Loads ◽  
Base Shear ◽  
Building Frames ◽  
Building Frame ◽  
History Analysis ◽  
Hilly Region

Abstract: Due to sloping land and high seismically active zones, designing and construction of multistory buildings in hilly regions is always a challenge for structural engineers. This review paper focuses to establish a review study on the Possible Types of building frame configuration in the hilly region and he behavior of Such building frames under seismic loading conditions, and (3) The recent research and developments to make such frames less vulnerable to earthquakes. This paper concludes that the dynamics characteristics of such buildings are significantly different in both horizontal and vertical directions, resulting in the center of mass and center of stiffness having eccentricity at point of action and not vertically aligned for different floors. When such frames are subjected to lateral loads, due to eccentricity it generates torsion in the frame. Most of the studies agree that the buildings resting on slanting ground have higher displacement and base shear compared to buildings resting on plain ground and the shorter column attracts more forces and undergoes damage when subjected to earthquake. Keywords: Building frame configuration, Seismic behavior, Dynamic characteristics, Response spectrum analysis, time history analysis.

Analysis of Effective Location of Shear Wall for High Rise Building with U – Configuration

2021 ◽  
Vol 23 (2) ◽  
pp. 167-176
Author(s):  
Sekar Mentari ◽  
Rosi Nursani
Keyword(s):  
Lateral Displacement ◽  
Center Of Mass ◽  
Shear Walls ◽  
Shear Wall ◽  
Rotational Axis ◽  
Moment Frame ◽  
Earthquake Loads ◽  
High Rise ◽  
Live Loads ◽  
Special Moment Frame

Indonesia is one of the countries that is prone to earthquakes. In addition to the dead loads, superimposed dead loads, and live loads, the design of buildings in Indonesia must be concerned with earthquake loads. Installing shear walls in the building structure as the Special Moment Frame Dual System is one of a solution to withstand earthquake loads. However, the location of shear walls must be considered, especially in buildings with horizontal irregularities. This study aims to determine the optimum location of the shear walls in a 10-storey building that has U-configuration with dynamic earthquake loads. This research is a numerical simulation ran by modelling the structure with software. To know the effect of the shear wall’s location on a building, several variations of the shear wall configuration with different positions have been conducted. It can be seen the lateral displacement of each floor and the shear force are the response structure to withstand the dynamic earthquake loads. Shear walls that are located close to the center of mass of the building are the optimum variation because the position of the shear wall is the closest to the core area of the building, which is the rotational axis of the building.

Long bone cross-sectional geometry

2020 ◽  
pp. 307-320
Author(s):  
Christopher B. Ruff ◽  
Ryan W. Higgins ◽  
Kristian J. Carlson
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Lateral Displacement ◽  
Center Of Mass ◽  
Gait Pattern ◽  
Locomotor Behavior ◽  
The Body ◽  
Long Bone ◽  
Cross Sectional ◽  
Body Center

Long bone diaphyseal cross-sectional geometries reflect the mechanical properties of the bones, and can be used to aid in inferences of locomotor behavior in extinct hominins. This chapter considers all available long bone diaphyseal and femoral neck cross-sections of specimens from Sterkfontein Member 4, and presents comparisons of these section properties and other cross-sectional dimensions with those of other early hominins as well as modern samples. The cross-sectional geometry of the Sterkfontein Member 4 long bone specimens suggests some similarities to, but also interesting differences in, mechanical loading of these elements relative to modern humans. The less asymmetric cortical bone distribution in the Sterkfontein femoral necks is consistent with other evidence above indicating an altered gait pattern involving lateral displacement of the body center of mass over the stance limb. The relatively very strong upper limb of StW 431 implies that arboreal behavior formed a significant component of its locomotor repertoire. Bipedal gait may have been less efficient and arboreal climbing more prevalent in the Sterkfontein hominins.

Transient Tracers and Anthropogenic Carbon in Central Labrador Sea: a Multi-Decadal Study

2020 ◽  
Author(s):  
Lorenza Raimondi ◽  
Kumiko Azetsu-Scott ◽  
Toste Tanhua ◽  
Igor Yashayaev ◽  
Doug Wallace
Keyword(s):  
Time Series ◽  
Temporal Variability ◽  
Dissolved Inorganic Carbon ◽  
Mixed Layer Depth ◽  
Monitoring Program ◽  
Time History ◽  
Labrador Sea ◽  
Full Time ◽  
Time Varying ◽  
Anthropogenic Carbon

<p>Over the last thirty years the Bedford Institute of Oceanography (BIO) has been maintaining the Atlantic Zone Off-Shore Monitoring Program (AZOMP), which includes annual occupation of several sections and stations in the Northwest Atlantic Ocean. Among these, the AR7W line across the Labrador Sea has one of the longest time-series where both transient tracers and dissolved inorganic carbon (DIC) have been collected since the early 1990s.</p><p>Among multiple transient tracers that have been measured along this transect (CFC-11, CFC-113, CCl<sub>4</sub> and SF<sub>6</sub>), only measurement of CFC-12 extends over the full time-series from 1992 to 2018, overlapping with DIC observations. Measurements of CFC-12 were also available for a previous cruise in 1986, extending the time-series to three decades.</p><p>In this work we present the temporal variability of CFC-12 (1986-2016) and DIC (1992-2016) concentrations as well as their distribution in the major water masses of the region.</p><p>The CFC-12 data are used to reconstruct the time-history of the tracer’s saturation at the time of convection based on multiple regression with the atmospheric input function of CFC-12 and the annual maximum mixed layer depth. The so-modelled time-varying saturation is employed to relax the constant saturation assumption of the Transit Time Distribution (TTD) method, allowing for a better estimate of anthropogenic carbon (C<sub>ant</sub>) in the region.</p><p>We present the column inventories and storage rate of C<sub>ant</sub> in central Labrador Sea between 1986 and 2016 obtained using the TTD method with time-varying saturation. We compare these estimates with a classical TTD approach that assumes constant saturation, and we highlight the differences in trends and magnitudes obtained with the two approaches.    </p><p>Finally, our work shows the multi-decadal dataset of DIC in the Labrador Sea which enables a comparison between the TTD-based C<sub>ant</sub> estimates and the measured DIC trends, providing insights into temporal variability of natural carbon in the region.</p>

Structural Reliability Analysis with Multi-Failure Models Using High-Dimensional Model Representation

2013 ◽  
Vol 351-352 ◽  
pp. 1648-1651
Author(s):  
Wei Tao Zhao ◽  
Lei Jia ◽  
Cheng Kui Niu
Keyword(s):  
Failure Probability ◽  
Parallel System ◽  
Model Representation ◽  
High Dimensional ◽  
High Dimensional Model Representation ◽  
State Function ◽  
Model Assessment ◽  
Series System ◽  
Dimensional Model ◽  
Failure Models

Based on the high dimensional model representation (HDMR) and Monte Carlo simulation (MCS), this paper presents the improved method used to evaluate the failure probability of the system with multi-failure models. The HDMR is a general set of quantitative model assessment and analysis tools for capturing the high-dimensional relationships between sets of input and output model variables. Once the limit state function is defined by using the HDMR, the failure probability can be obtained by using the MCS without increasing computational efforts. The series and parallel system are considered in this paper, a numerical example is presented to demonstrate the efficiency and the accuracy of the proposed method. It is shown that the efficiency of the HDMR are both high in terms of series system and parallel system, the accuracy can be acceptable with respect to series system, and the accuracy can not be acceptable with respect to parallel system.

Non-Linear Step-by-Step Seismic Response and the Push-Over Analysis Comparison of a Reinforced Concrete of Ductile Frames 15 Level Building

2008 ◽  
Vol 385-387 ◽  
pp. 229-232
Author(s):  
Jorge A. Avila ◽  
Eduardo Martínez
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Zone ◽  
Lateral Loads ◽  
Base Shear ◽  
Non Linear ◽  
Story Drift ◽  
Lateral Displacements ◽  
Group B ◽  
Level Building

Based on a ductile frames 15 level building, a non-linear analysis with increased monotonically lateral loads (Push-Over) was made in order to determine its collapse and its principal responses were compared against the elastic and inelastic time-history seismic responses determined with the SCT-EW-85 record. The seismic-resistance design and faced to gravitational loads was made according to the Complementary Technical Norms of Concrete Structures Design (NTC-Concrete) and the NTC-Seismic of the Mexico City Code (RDF-04), satisfying the limit service states (relative lateral displacement between story height maximum relations, story drifts ≤ 0.012) and failure (seismic behavior factor, Q= 3). The compressible (soft) seismic zone IIIb and the office use type (group B) were considered. The non-linear responses were determined with nominal and over-resistance effects. The comparison were made with base shear force–roof lateral displacement relations, global distribution of plastic hinges, failure mechanics tendency, lateral displacements and story drift and its distribution along the height of the building, local and global ductility demands, etc. For the non-linear static analysis with increased monotonically lateral loads, it was important to select the type of lateral forces distribution.

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