Proposed Standard Fatigue Truck in Montane Speedway of Southwest China

2011 ◽  
Vol 90-93 ◽  
pp. 1239-1244
Author(s):  
Ji Wei Zhong ◽  
Kun Quan Huang ◽  
Xing Xin Li
Keyword(s):  
Effective Stress ◽  
Southwest China ◽  
Peak Stress ◽  
Traffic Data ◽  
Stress Range ◽  
Weigh In Motion ◽  
Bridge Model ◽  
Actual Damage ◽  
The Moment ◽  
Fatigue Evaluation

The fatigue truck model is an important parameter in a fatigue evaluation, a 3-axle fatigue truck model was developed based on the weigh-in-motion traffic data and an analytical bridge model in the montane highway of Southwest China. The truck traffic data shows that the fatigue damage was dominated by the 6-axles trucks,a 3-axle fatigue truck model was developed based on the 6-axle truck statistic data,the damage accumulations caused by the Proposed fatigue truck righty meet the actual damage accumulations. Based on the cumulative probabilitie of the moment ranges, the peak stress range is suggested to be a stress level at 3 times of the effective stress range because of overload,however,the ratio of the effective stress in AASHTO was 2 times.The damage accumulations obtained from the simulation of the truck database were compared with BS5400,AASHTO and Proposed fatigue truck, Proposed fatigue truck and AASHTO fatigue truck with the actural daily flow of trucks are suggested in the montane speedway of Southwest China ,BS5400 is impropriety which relatively overestimate the damage.

scholarly journals Identifying damage on a bridge using rotation-based Bridge Weigh-In-Motion

2020 ◽  
Author(s):  
E. J. OBrien ◽  
J. M. W. Brownjohn ◽  
D. Hester ◽  
F. Huseynov ◽  
M. Casero
Keyword(s):  
Damage Detection ◽  
Traffic Management ◽  
Traffic Data ◽  
Simply Supported ◽  
Weigh In Motion ◽  
Bridge Model ◽  
Wide Range ◽  
Bridge Condition Assessment ◽  
Bridge Damage ◽  
Bridge Weigh In Motion

Abstract Bridge Weigh-in-Motion (B-WIM) systems use the bridge response under a traversing vehicle to estimate its axle weights. The information obtained from B-WIM systems has been used for a wide range of applications such as pre-selection for weight enforcement, traffic management/planning and for bridge and pavement design. However, it is less often used for bridge condition assessment purposes which is the main focus of this study. This paper presents a bridge damage detection concept using information provided by B-WIM systems. However, conventional B-WIM systems use strain measurements which are not sensitive to local damage. In this paper the authors present a B-WIM formulation that uses rotation measurements obtained at the bridge supports. There is a linear relationship between support rotation and axle weight and, unlike strain, rotation is sensitive to damage anywhere in the bridge. Initially, the sensitivity of rotation to damage is investigated using a hypothetical simply supported bridge model. Having seen that rotation is damage-sensitive, the influence of bridge damage on weight predictions is analysed. It is shown that if damage occurs, a rotation-based B-WIM system will continuously overestimate the weight of traversing vehicles. Finally, the statistical repeatability of ambient traffic is studied using real traffic data obtained from a Weigh-in-Motion site in the U.S. under the Federal Highway Administration’s Long-Term Pavement Performance programme and a damage indicator is proposed as the change in the mean weights of ambient traffic data. To test the robustness of the proposed damage detection methodology numerical analysis are carried out on a simply supported bridge model and results are presented within the scope of this study.

scholarly journals Investigation of Weigh-in-Motion Measurement Accuracy on the Basis of Steering Axle Load Spectra

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3272 ◽  
Author(s):  
Dawid Rys
Keyword(s):  
Data Quality ◽  
Vehicle Speed ◽  
Traffic Data ◽  
Obvious Effect ◽  
Road Infrastructure ◽  
Load Spectra ◽  
Weigh In Motion ◽  
Infrastructure Design ◽  
Load Sensor ◽  
Measurement Results

Weigh-in-motion systems are installed in pavements or on bridges to identify and reduce the number of overloaded vehicles and minimise their adverse effect on road infrastructure. Moreover, the collected traffic data are used to obtain axle load characteristics, which are very useful in road infrastructure design. Practical application of data from weigh-in-motion has become more common recently, which calls for adequate attention to data quality. This issue is addressed in the presented paper. The aim of the article is to investigate the accuracy of 77 operative weigh-in-motion stations by analysing steering axle load spectra. The proposed methodology and analysis enabled the identification of scale and source of errors that occur in measurements delivered from weigh-in-motion systems. For this purpose, selected factors were investigated, including the type of axle load sensor, air temperature and vehicle speed. The results of the analysis indicated the obvious effect of the axle load sensor type on the measurement results. It was noted that systematic error increases during winter, causing underestimation of axle loads by 5% to 10% for quartz piezoelectric and bending beam load sensors, respectively. A deterioration of system accuracy is also visible when vehicle speed decreases to 30 km/h. For 25% to 35% of cases, depending on the type of sensor, random error increases for lower speeds, while it remains at a constant level at higher speeds. The analysis also delivered a standard steering axle load distribution, which can have practical meaning in the improvement of weigh-in-motion accuracy and traffic data quality.

Fatigue Evaluation Incorporating Multiaxiality of Stress States

2005 ◽  
Author(s):  
Somnath Chattopadhyay
Keyword(s):  
Stress Distribution ◽  
Stress Concentrator ◽  
Experimental Studies ◽  
Peak Stress ◽  
Thermal Fluctuations ◽  
Feed Water ◽  
Critical Factors ◽  
Water Nozzle ◽  
Stress States ◽  
Fatigue Evaluation

In this work the effects of multiaxiality on the fatigue evaluation by the ASME Boiler and Pressure Vessel Code procedures have been assessed. The conservatism associated with the Ke factor has been critically appraised for fatigue evaluation using a design example of a feed water nozzle subjected to pressure and thermal fluctuations. A fictitious stress concentrator is applied to account for the ratio of the peak stress to the stress linearized through the thickness of the section under consideration. The effect of the traxiality of the stress distribution has also been assessed using the same design example for fatigue evaluations. Additional analytical and experimental studies have been recommended to study these important critical factors for fatigue assessment.

Research on Integrated and Portable Weigh-in-Motion Scale

2012 ◽  
Vol 192 ◽  
pp. 149-153
Author(s):  
Liang Hao
Keyword(s):  
Data Collection ◽  
Dynamic Characteristic ◽  
Strain Gauge ◽  
High Accuracy ◽  
Traffic Data ◽  
Ansys Software ◽  
Weigh In Motion ◽  
Traffic Data Collection ◽  
Dynamic Weighing

The integrated dynamic weighing scale with a high accuracy was developed based on analyzing the loads when vehicles passed on the weighing scale. The ANSYS software was applied to determine the sensor’s foil strain gauge position and the dynamic characteristic was verified through the experiment; meanwhile the hardware and measuring software in the system were simply introduced in this article. Finally through the experiments the Weigh-In-Motion (WIM) system can be used in traffic data collection and is assistant tool for overload check.

On Effective Stress Range Factor in Fatigue

1980 ◽  
Vol 102 (1) ◽  
pp. 147-152 ◽  
Author(s):  
K. M. Lal ◽  
S. B. L. Garg ◽  
I. Le May
Keyword(s):  
Fatigue Crack ◽  
Crack Closure ◽  
Effective Stress ◽  
Stress Ratio ◽  
Stress Amplitude ◽  
Simplified Model ◽  
Strain Hardening Exponent ◽  
Stress Range ◽  
Stress Cycles ◽  
Good Agreement

A detailed analysis of crack closure during fatigue crack propagation has been made using a simplified model. In addition, experimental work has been conducted using eddy current methods to determine crack closure. It was found that the effective stress range factor, U, depends on the applied stress range, stress ratio, yield strength and strain hardening exponent of the material, and that its value stabilizes in about 10 stress cycles for constant stress amplitude loading. Experimental and predicted results were seen to be in good agreement.

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