scholarly journals Effect of the Dynamic Load on Stresses in a Deck Pavement with an Interlayer Contact Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Xuntao Wang ◽  
Jianhu Feng ◽  
Hu Wang ◽  
Shidi Hong ◽  
Xiaohan Cheng ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Dynamic Load ◽  
Asphalt Concrete ◽  
Element Model ◽  
Superposition Method ◽  
Vehicle Speed ◽  
Random Surface ◽  
Bonding Condition ◽  
Concrete Layer ◽  
Road Surface Roughness

Random surface roughness of bridge deck pavement just like random road surface roughness was simulated by the harmony superposition method in this paper. The dynamic load of vehicle was calculated by the random surface roughness of the deck pavement and the quarter-car model. A finite element model of a box girder bridge and its deck pavement was established, and the bonding condition between the adjacent layers was assumed to be contact bonding condition. The stress values of the asphalt concrete layer were calculated and analyzed when surface roughness condition, vehicle speed, and disengaging area changed. Results show that random surface roughness of deck pavement affected the stress trend of the asphalt concrete layer obviously. The appearance of disengaging area would increase the stress values of the asphalt concrete layer and the normal tensile stress value between the asphalt concrete layer and the waterproof layer. This would speed up the damage of the asphalt concrete layer and enlarge further the disengaging area.

Prediction of Fatigue Failure at Asphalt Concrete Layer Interface from Monotonic Testing

2015 ◽  
Vol 2507 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Cristina Tozzo ◽  
Antonio D'Andrea ◽  
Imad L. Al-Qadi
Keyword(s):  
Shear Strength ◽  
Asphalt Concrete ◽  
Three Dimensional ◽  
Element Model ◽  
Stress Conditions ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Strength Failure ◽  
Concrete Layer ◽  
Important Approach

This study investigated the characterization of interface shear behavior in asphalt concrete through the estimation of the stress ratio (SR). This parameter, originally identified as the ratio between predicted interface stress from a finite element model (FEM) and interface shear strength at the corresponding normal stress, was assumed to be dynamic. As part of the experimental plan, monotonic tests on double-layered asphalt specimens were performed. Dynamic evaluations of the number of repetitions to failure under several stress conditions, equal to or higher than stresses computed from an FEM of the pavement structure, were also performed. The failure curves of the two testing modalities show similar patterns on the Mohr plane. The Hoek–Brown shear strength failure criterion and the three-dimensional surface that best fits the dynamic outcomes were considered. In this scenario, the SR referred to the proportion between the applied shear stress conditions in the dynamic modality and the maximum stress from monotonic tests. For the same predicted failure repetitions, SR assumed a constant value. Correlating monotonic and dynamic results could be an important approach both in furthering knowledge of interface shear strength and in predicting information about failure under repetitive loading applications based on simple monotonic tests.

Study on Elasto-Plastic Response of the Unsupported Random Launching Site for the Missile

2014 ◽  
Vol 945-949 ◽  
pp. 1274-1279
Author(s):  
Jie Ren ◽  
Xiao He Zhou ◽  
Da Wei Ma ◽  
Jian Lin Zhong
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Asphalt Concrete ◽  
Element Model ◽  
Plastic Response ◽  
Center Point ◽  
Concrete Layer ◽  
The Finite Element Model ◽  
Launching Site ◽  
Sedimentation Value

The elasto-plastic response of the launching site for a missile during the launching phase is studied. Firstly, simulate the asphalt concrete layer with Drucker-Prager/Creep creeping model. Secondly, the finite element model of the launching site is built. Finally, research the elasto-plastic response of launching site under the launch canister under catapult load. The results show that: integral subsidence appears in the unsupported random launching site under catapult load, the sedimentation value of the center point is greater than that in the edge of the launching site under catapult load, the edge of the launching site is higher as a whole than the middle, the stress at the edge of the catapult load is the greatest, the instantaneous stress of the center point under catapult load is the greatest when the launching load finishes.

A Computerized Method for Dynamic Response of Vehicle-Bridge Interaction System under Various Conditions

2013 ◽  
Vol 639-640 ◽  
pp. 1214-1219
Author(s):  
Yao Xiao ◽  
Zheng Qing Chen ◽  
Xu Gang Hua
Keyword(s):  
Surface Roughness ◽  
Dynamic Effect ◽  
Integrated System ◽  
Road Surface ◽  
Dynamic Responses ◽  
Superposition Method ◽  
The Road ◽  
Computerized Method ◽  
Road Surface Roughness ◽  
The Impact

A computerized method is presented for computing the dynamic responses of bridges under moving vehicles. The bridge and vehicle are treated as integrated system and modal superposition method is applied to transfer the equation of motion into modal coordinate system. The road roughness/unevenness is also considered. The effects of different vehicle models, vehicle passing speed and road surface roughness on bridge dynamic responses are studied. The impact factor representing the dynamic effect of passing vehicle is calculated for different road surface roughness

Random Dynamic Response Analysis of Asphalt Pavement Based on the Vehicle-Pavement Interaction

2015 ◽  
Vol 744-746 ◽  
pp. 1288-1297 ◽  
Author(s):  
Qian Li ◽  
Jun Qing Liu ◽  
Hong Liu
Keyword(s):  
Dynamic Response ◽  
Dynamic Load ◽  
Asphalt Pavement ◽  
Element Model ◽  
Response Analysis ◽  
Vehicle Speed ◽  
Tire Pressure ◽  
Random Load ◽  
Response Characteristics ◽  
Pavement Roughness

In order to analyze the dynamic response of asphalt pavement under vehicle load, the random characteristic of pavement roughness was considered and the vehicle was simplified into 1/2 model with four freedom degrees when establishing the dynamic load model. Then the sequence of the random dynamic load coefficient was obtained by developing a MATLAB program based on the incremental Newmark-β method. Based on the plane strain assumption, a two-dimensional layered finite element model of asphalt pavement was established by ABAQUS software. Then the dynamic load coefficient was used to modify tire pressure that would be applied on the ABAQUS model. Then dynamic response rule of the model and how it was effected by vehicle speed were studied under random load. The results show that under the condition of random load, dynamic response of the pavement structure exhibiting a fluctuation trend as vehicle speed increases and the dynamic response characteristics of each point is different.

Field Investigation into Effects of Vehicle Speed and Tire Pressure on Asphalt Concrete Pavement Strains

1996 ◽  
Vol 1539 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Karim Chatti ◽  
Hyung B. Kim ◽  
Kyong K. Yun ◽  
Joe P. Mahoney ◽  
Carl L. Monismith
Keyword(s):  
Asphalt Concrete ◽  
Pressure Effect ◽  
Field Investigation ◽  
Vehicle Speed ◽  
Tire Pressure ◽  
Mount Vernon ◽  
Concrete Layer ◽  
Speed Effect ◽  
Longitudinal Strains ◽  
Percent Decrease

An asphalt concrete section on a test track in the PACCAR Technical Center in Mount Vernon, Washington, was fitted with strain gauges at the surface and in pavement cores and tested using an instrumented truck operated at different speeds and with different tire pressures. The field test results are presented. The results indicate that the effects of both vehicle speed and tire pressure–contact area on pavement strains are significant: increasing vehicle speed from 2.7 km/hr (1.7 mi/hr) to 64 km/hr (40 mi/hr) caused a decrease of approximately 30 to 40 percent in longitudinal strains at the bottom of the asphalt concrete layer, which was 137 mm (5.4 in.) thick. The speed effect on transverse strains is lower, causing only a 15 to 30 percent decrease. Reducing tire pressure from 620 kPa (90 psi) to 214 kPa (30 psi) caused a decrease of approximately 20 to 45 percent in the horizontal strains at the bottom of the asphalt concrete layer. The pressure effect on surface strains was significantly lower, causing only a 5 to 20 percent decrease. The speed effect was somewhat reduced at lower pressures, and the pressure effect was reduced at higher speeds.

scholarly journals Structural and Acoustic Responses of a Submerged Stiffened Conical Shell

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Meixia Chen ◽  
Cong Zhang ◽  
Xiangfan Tao ◽  
Naiqi Deng
Keyword(s):  
Conical Shell ◽  
Element Model ◽  
Analytical Models ◽  
Superposition Method ◽  
Far Field ◽  
Fluid Loading ◽  
Low Frequencies ◽  
Structural Responses ◽  
The Individual ◽  
Field Sound

This paper studies the vibrational behavior and far-field sound radiation of a submerged stiffened conical shell at low frequencies. The solution for the dynamic response of the conical shell is presented in the form of a power series. A smeared approach is used to model the ring stiffeners. Fluid loading is taken into account by dividing the conical shell into narrow strips which are considered to be local cylindrical shells. The far-field sound pressure is solved by the Element Radiation Superposition Method. Excitations in two directions are considered to simulate the loading on the surface of the conical shell. These excitations are applied along the generator and normal to the surface of the conical shell. The contributions from the individual circumferential modes on the structural responses of the conical shell are studied. The effects of the external fluid loading and stiffeners are discussed. The results from the analytical models are validated by numerical results from a fully coupled finite element/boundary element model.

The effect of a footprint on perceived surface roughness

1986 ◽  
Vol 405 (1829) ◽  
pp. 303-327 ◽  
Keyword(s):  
Surface Roughness ◽  
Weighting Function ◽  
Sampling Interval ◽  
Asymptotic Convergence ◽  
Reference Surface ◽  
Two Dimensional ◽  
Random Surface ◽  
Spectral Density Functions ◽  
Continuous Theory ◽  
Discrete Theory

A two-dimensional homogeneous random surface { y ( X )} is generated from another such surface { z ( X )} by a process of smoothing represented by y ( X ) = ∫ ∞ d u w ( u – X ) z ( u ), where w ( X ) is a deterministic weighting function satisfying certain conditions. The two-dimensional autocorrelation and spectral density functions of the smoothed surface { y ( X )} are calculated in terms of the corresponding functions of the reference surface { z ( X )} and the properties of the ‘footprint’ of the contact w ( X ). When the surfaces are Gaussian, the statistical properties of their peaks and summits are given by the continuous theory of surface roughness. If only sampled values of the surface height are available, there is a corresponding discrete theory. Provided that the discrete sampling interval is small enough, profile statistics calculated by the discrete theory should approach asymptotically those calculated by the continuous theory, but it is known that such asymptotic convergence may not occur in practice. For a smoothed surface { y ( X )} which is generated from a reference surface { z ( X )} by a ‘good’ footprint of finite area, it is shown in this paper that the expected asymptotic convergence does occur always, even if the reference surface is ideally white. For a footprint to be a good footprint, w ( X ) must be continuous and smooth enough that it can be differentiated twice everywhere, including at its edges. Sample calculations for three footprints, two of which are good footprints, illustrate the theory.

Analytical Study of Effects of Truck Tire Pressure on Pavements with Measured Tire–Pavement Contact Stress Data

2005 ◽  
Vol 1919 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Randy B. Machemehl ◽  
Feng Wang ◽  
Jorge A. Prozzi
Keyword(s):  
Conventional Method ◽  
Contact Stress ◽  
Asphalt Concrete ◽  
Pressure Effects ◽  
Tire Pressure ◽  
Variance Model ◽  
Truck Tire ◽  
Concrete Layer ◽  
Pavement Structures ◽  
Asphalt Concrete Pavement

Truck tire inflation pressure plays an important role in the tire–pavement interaction process. As a conventional approximation method in many pavement studies, tire–pavement contact stress is frequently assumed to be uniformly distributed over a circular contact area and to be simply equal to the tire pressure. However, recent studies have demonstrated that the tire–pavement contact stress is far from uniformly distributed. Measured tire–pavement contact stress data were input into an elastic multilayer pavement analysis program to compute pavement immediate responses. Two asphalt concrete pavement structures, a thick pavement and a thin pavement, were investigated. Major pavement responses at locations in the pavement structures were computed with the measured tire–pavement contact stress data and were compared with the conventional method. The computation results showed that the conventional method tends to underestimate pavement responses at low tire pressures and to overestimate pavement responses at high tire pressures. A two-way analysis of variance model was used to compare the pavement responses to identify the effects of truck tire pressure on immediate pavement responses. Statistical analysis found that tire pressure was significantly related to tensile strains at the bottom of the asphalt concrete layer and stresses near the pavement surface for both the thick and thin pavement structures. However, tire pressure effects on vertical strain at the top of the subgrade were minor, especially in the thick pavement.

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