Fatigue Stress Spectra and Reliability Evaluation of Short- to Medium-Span Bridges under Stochastic and Dynamic Traffic Loads

With the steadily growing of global transportation market, the traffic load has increased dramatically over the past decades, which may develop into a risk source for existing bridges. The simultaneous presence of heavy trucks that are random in nature governs the serviceability limit for large bridges. This study investigated probabilistic traffic load effects on large bridges under actual heavy traffic load. Initially, critical stochastic traffic loading scenarios were simulated based on millions of traffic monitoring data in a highway bridge in China. A methodology of extrapolating maximum traffic load effects was presented based on the level-crossing theory. The effectiveness of the proposed method was demonstrated by probabilistic deflection investigation of a suspension bridge. Influence of traffic density variation and overloading control on the maximum deflection was investigated as recommendations for designers and managers. The numerical results show that the congested traffic mostly governs the critical traffic load effects on large bridges. Traffic growth results in higher maximum deformations and probabilities of failure of the bridge in its lifetime. Since the critical loading scenario contains multi-types of overloaded trucks, an effective overloading control measure has a remarkable influence on the lifetime maximum deflection. The stochastic traffic model and corresponding computational framework is expected to be developed to more types of bridges.

Section: Traffic Monitoring Data and Traffic Flow Simulationsupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Evaluating Probabilistic Traffic Load Effects on Large Bridges Using Long-Term Traffic Monitoring Data

Liu

2019

“…At this time, the dynamic displacement of the bridge is large, and the structural behavior characteristics obtained from it are more obvious. According to the dynamic displacement of the bridge, vehicle type, driving speed, rough road conditions, etc., the fatigue stress of short-span and mid-span bridges under dynamic traffic loads can be modeled to evaluate the fatigue reliability of the bridge [23].…”

Section: Experiments and Analysismentioning

confidence: 99%

Refactoring and Optimization of Bridge Dynamic Displacement Based on Ensemble Empirical Mode Decomposition

Zou

Chen

Liu

2019

Considering the lack of precision in transforming measured micro-electro-mechanical system (MEMS) accelerometer output signals into elevation signals, this paper proposes a bridge dynamic displacement reconstruction method based on the combination of ensemble empirical mode decomposition (EEMD) and time domain integration, according to the vibration signal traits of a bridge. Through simulating bridge analog signals and verifying a vibration test bench, four bridge dynamic displacement monitoring methods were analyzed and compared. The proposed method can effectively eliminate the influence of low-frequency integral drift and high-frequency ambient noise on the integration process. Furthermore, this algorithm has better adaptability and robustness. The effectiveness of the method was verified by field experiments on highway elevated bridges.

“…For example, reference [ 1 ] proposes a new anti-lock braking system (ABS) for electric vehicles using a virtual load, and a sliding-mode controller is proposed for regulating the slip ratio to reach the ideal value for road adhesion; Reference [ 2 ] presents a detection method for damage location of beam structures based on the mode shape extracted from the dynamic load of the vehicle to reduce the impact of the external environment; the presented method has been tested with experiments, and the results show that the accuracy of location can exceed 97%; The road load is widely used in automotive durability testing; in order to achieve the durability of the entire vehicle, it is necessary for the entire vehicle, system, subsystem and parts to meet their respective durability requirements [ 3 ]; Automobile operational stability is also closely related to the road load, the main test items are: a low-speed steering and portability test, steady-state steering characteristic test, transient yaw response test, automotive return-to-negative capability test, steering wheel angle pulse test, steering wheel intermediate position manipulation stability test, etc. [ 4 ]; A key factor in the test of automobile fatigue life is accurate acquisition of the random load imposed on the tested item [ 5 ]. Mass production is impossible unless the prototype test has achieved complete success.…”

Section: Introductionmentioning

confidence: 99%

Wheel Force Sensor-Based Techniques for Wear Detection and Analysis of a Special Road

Yan

Zhang

Wang

2018

Automobile proving ground is important for the research of vehicles which are used for vehicle dynamics, durability testing, braking testing, etc. However, the road in automobile proving grounds will inevitably be damaged with the extension of the service life. In most previous research, equipment similar to a laser profilometer was used to detect the quality of the road, the principle of which is to reflect the quality of the road by measuring the roughness of the pavement. This method ignores the elastic deformation of the road itself when the vehicle is traveling and it is difficult to compensate for the error. Therefore, this paper presents a new method based on a force sensor to reduce the impact of elastic deformation, such as tire deformation, pavement deformation, and wheel rim deformation. In this study, force sensors mounted on the wheels collect the three-dimensional dynamic force of the wheel. The presented method has been tested with two sets of cobblestone road loads, and the result shows that the load intensities imposed by the test vehicle on the target road are 88.3%, 91.0%, and 92.05% of the intensity of the load imposed by the test vehicle on a standard road in three respective dimensions. It is clear that the proposed method has strong potential effectiveness to be applied for wear detection and analysis of a special road.