scholarly journals New Damage Evolution Law for Steel–Asphalt Concrete Composite Pavement Considering Wheel Load and Temperature Variation

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3723 ◽  
Author(s):  
Xunqian Xu ◽  
Xiao Yang ◽  
Wei Huang ◽  
Hongliang Xiang ◽  
Wei Yang
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
Steel Bridge ◽  
Wheel Load ◽  
Evolution Law ◽  
Long Span ◽  
Fatigue Design ◽  
Epoxy Asphalt

Epoxy asphalt (EA) concrete is widely used in constructing long-span steel bridge pavements (SBDPs). This study aims to derive a fatigue damage evolution law, conducting an experimental investigation of SBDP. First, a general theoretical form of the fatigue damage evolution law of materials is established based on the thermal motion of atoms. Then, fatigue experiments demonstrate that this evolution law well represents the known damage–life relationships of SBDP. Taking into account the experimental relationships between damage and fatigue life under symmetrical cyclic loadings with different overload amplitudes and temperature variations, a detailed damage evolution law is deduced. Finally, the role of damage accumulation is discussed on the basis of the proposed damage evolution law for the extreme situation of heavy overload and severe environments. The results show that both heavy loading and falling temperatures increase the fatigue damage of SBDP considerably. EA shows a fatigue life two to three times longer than that of modified matrix asphalt (SMA) or guss asphalt (GA). For the same thickness, EA pavement is demonstrated to be more suitable for an anti-fatigue design of large-span SBDP under high traffic flows and low temperatures.

scholarly journals New Damage Evolution Law for Epoxy Asphalt Concrete in Long-Span Steel Bridge Considering Wheel Load and Temperature Variation

2019 ◽  
Author(s):  
Xun Qian Xu ◽  
Xiao Yang ◽  
Wei Huang ◽  
Hong Liang Xiang ◽  
Wei Yang
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
Steel Bridge ◽  
Wheel Load ◽  
Evolution Law ◽  
Long Span ◽  
Fatigue Design ◽  
Epoxy Asphalt ◽  
Winter Temperatures

Epoxy asphalt (EA) concrete is widely used in constructing long-span steel bridge pavements (SBDPs). This study aims to derive a fatigue damage evolution law, conducting an experimental investigation of SBDP. First, a general theoretical form of the fatigue damage evolution law of materials is established based on the thermal motion of atoms. Then, fatigue experiments demonstrate that this evolution law well represents the known damage–life relationships of SBDP. Taking into account the experimental relationships between damage and fatigue life under symmetrical cyclic loadings with different overload amplitudes and temperature variations, a detailed damage evolution law is deduced. Finally, the role of damage accumulation is discussed on the basis of the proposed damage evolution law for the extreme situation of heavy overload and severe environments. The results show that both heavy loading and falling temperatures increase the fatigue damage of SBDP considerably; therefore, SBDP should avoid heavy loading combined with winter temperatures. EA shows a fatigue life two to three times longer than that of modified matrix asphalt (SMA) or guss asphalt (GA). For the same thickness, EA pavement is demonstrated to be more suitable for an anti-fatigue design of large-span SBDP under high traffic flows and low temperatures.

New damage evolution law for modeling fatigue life of asphalt concrete surfacing of long-span steel bridge

2020 ◽  
Vol 259 ◽  
pp. 119795 ◽  
Author(s):  
Xun Qian Xu ◽  
Xiao Yang ◽  
Wei Yang ◽  
Xin Feng Guo ◽  
Hong Liang Xiang
Keyword(s):  
Fatigue Life ◽  
Asphalt Concrete ◽  
Damage Evolution ◽  
Steel Bridge ◽  
Evolution Law ◽  
Long Span

Concurrent multi-scale fatigue damage evolution simulation method for long-span steel bridges

2017 ◽  
Vol 28 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Bin Sun ◽  
You-Lin Xu ◽  
Qing Zhu ◽  
Zhaoxia Li
Keyword(s):  
Fatigue Damage ◽  
Damage Evolution ◽  
Large Scale ◽  
Simulation Method ◽  
Steel Bridges ◽  
Steel Bridge ◽  
Structural Failure ◽  
Evolution Simulation ◽  
Multi Scale ◽  
Long Span

Fatigue damage is one of the leading causes for structural failure of long-span steel bridges, but fatigue damage evolution of a long-span steel bridge is very complex. This study proposes a concurrent multi-scale fatigue damage evolution simulation method for long-span steel bridges from micro short crack nucleation and growth to macro structural component damage until mega structural failure. As a case study, the fatigue damage evolution of the Stonecutters Bridge in Hong Kong under cyclic vehicle loading is finally simulated using the proposed method. It shows that the proposed method is computationally feasible even for such a large scale structure. The method can provide a clear picture how micro short cracks grow into macro fatigue damage of structural components and eventually lead to mega structural failure.

Probabilistic Fatigue Damage Analysis of Long Span Suspension Bridge Due to Wind Induced Buffeting

2020 ◽  
Vol 980 ◽  
pp. 275-281
Author(s):  
Hu Jun
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Time History ◽  
Suspension Bridge ◽  
Wind Load ◽  
Strong Wind ◽  
Fatigue Reliability ◽  
Long Span ◽  
Fatigue Damage Analysis ◽  
Fluctuating Wind

In order to consider the fluctuating wind load induced fatigue problem of long span suspension bridge, fatigue reliability formula is modified by assuming the fatigue life is accord with the weibull distribution. Based on the accurate bridge buffeting analysis of time history, the stress time history of components of a suspension bridge in east sea China is simulated, and then the fatigue damages and reliabilities are calculated. The results indicate that the main cables and hangers have enough fatigue reliability under the fluctuating wind load, the fatigue failure will not occur; the stiffening girder has larger fatigue damage, under 40 / (m.s-1) mean wind speed action, the girder of mid-support section’s average fatigue life is only 3.103 years, so the girder’s damage under strong wind action should be taken seriously.

Impact of Soil Modeling on Fatigue Design of Lazy Wave Riser Systems

2019 ◽  
Author(s):  
Rupak Ghosh ◽  
Haydar Arslan
Keyword(s):  
Fatigue Life ◽  
Water Injection ◽  
Field Testing ◽  
Vertical Displacement ◽  
Soil Response ◽  
Fatigue Design ◽  
Steel Catenary Risers ◽  
Design Requirements ◽  
Seabed Stiffness

Abstract The Liza risers comprise production risers, water injection risers and gas injection risers, and a lazy wave configuration is selected considering FPSO motion, reservoir fluid and overall project execution requirements. During operation, the risers are expected to move cyclically with small vertical displacement amplitudes (e.g. 0.1% to 1% of the riser diameter), and a key design issue is the fatigue life of these risers at critical locations including the touch-down zone which will be governed by the seabed stiffness. The role of soil response on fatigue life of riser with buoyancy has been investigated through nonlinear finite element and comprehensive lab and field testing program. Published methodologies for determining seabed stiffness values for risers concentrate more on larger amplitude motions based on the design requirements of steel catenary risers. The paper presents the sensitivity of the fatigue life at TDP to various soil model and provides insight in the results. Also included is the importance of site specific soil investigation in the context of design of riser.

Fatigue Safety Factors for Deepwater Risers

2002 ◽  
Author(s):  
B. Stahl ◽  
H. Banon
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Safety Factor ◽  
Damage Index ◽  
Rational Approach ◽  
Fatigue Reliability ◽  
Safety Factors ◽  
Fatigue Design ◽  
Uncertainty Parameters ◽  
Deepwater Risers

Fatigue life is governed by a number of variables that are highly uncertain. The safety factor on fatigue life is used in a deterministic way to account for the estimated fatigue damage uncertainty. High uncertainties lead to high fatigue safety factors, and vice versa. Evaluation of the uncertainties in the variables governing fatigue design provides a grip on what the safety factor should be. This paper addresses riser fatigue using a fatigue reliability model that is relatively simple but still captures the important elements of the fatigue problem. The bias and uncertainty of stress range are extremely important parameters in design against fatigue. This is due not only to the fact that these parameters are highly uncertain, but also to the fact that they are greatly amplified in the fatigue damage equation by the ‘slope’ m of the S-N curve. The Palmgren-Miner fatigue damage index and the intercept value of the S-N curve are additional important variables in fatigue design. A model for combining wave-induced and vortex-induced vibration (VIV) is introduced together with the best available data and reference to industry work in this technology area. A recently completed joint industry project on riser reliability provides good calibration points for the critical fatigue reliability variables. Reliability and sensitivity studies are performed to demonstrate the effect of the uncertainty parameters. An approach to selecting deterministic fatigue design factors that yield specified reliability targets is developed and illustrated. The study provides a rational approach to selecting safety factors for design of deepwater risers, taking into account both wave and VIV-induced fatigue damage.

Numerical Modeling and Simulation of Delamination Crack Growth in CF/Epoxy Composite Laminates under Cyclic Loading Using Cohesive Zone Model

2011 ◽  
Vol 326 ◽  
pp. 37-52 ◽  
Author(s):  
Hassan Ijaz ◽  
M Aurangzeb Khan ◽  
Waqas Saleem ◽  
Sajid Raza Chaudry
Keyword(s):  
Crack Growth ◽  
Fatigue Damage ◽  
Composite Laminates ◽  
Damage Evolution ◽  
Composite Structures ◽  
Cohesive Zone Model ◽  
Fatigue Loading ◽  
Zone Model ◽  
Evolution Law ◽  
Delamination Crack

This paper presents the mathematical modelling of fatigue damage able to carry out simulation of evolution of delamination in the laminated composite structures under cyclic loadings. A new elastic fatigue damage evolution law is proposed here. A classical interface damage evolution law, which is commonly used to predict static debonding process, is modified further to incorporate fatigue delamination effects due to high cycle loadings. The proposed fatigue damage model is identified using Fracture Mechanics tests like DCB, ENF and MMB. Simulations of delamination under fatigue loading are performed and results are successfully compared with reported experimental data on HTA/6376C unidirectional material. Delamination crack growth with variable fatigue amplitude is also performed and simulation results show that the proposed fatigue damage law can also accommodate this variable amplitude phenomenon. A study of crack tip behaviour using damage variable evolution is also carried out in this paper. Finally the effect of mesh density on crack growth is also discussed.

Analysis on High Cycle Fatigue Properties and Fatigue Damage Evolution of TC25 Titanium Alloy

2016 ◽  
Vol 697 ◽  
pp. 658-663
Author(s):  
Rong Guo Zhao ◽  
Ya Feng Liu ◽  
Yong Zhou Jiang ◽  
Xi Yan Luo ◽  
Qi Bang Li ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Strain Hardening ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
High Cycle Fatigue ◽  
Damage Model ◽  
Fatigue Properties ◽  
Test Machine ◽  
Cycle Fatigue

The high cycle fatigue tests for smooth specimens of TC25 titanium alloy under different stress ratios are carried out on a MTS 809 Material Test Machine at a given maximum stress level of 917MPa at ambient temperature, the high cycle fatigue lifetimes for such alloy are measured, and the effects of stress amplitude and mean stress on high cycle fatigue life are analyzed. The initial resistance is measured at the two ends of smooth specimen of TC25 titanium alloy, every a certain cycles, the fatigue test is interrupted, and the current resistance values at various fatigue cycles are measured. The ratio of resistance change is adopted to characterize the fatigue damage evolution in TC25 titanium alloy, and a modified Chaboche damage model is applied to derive the fatigue damage evolution equation. The results show that the theoretical calculated values agree well with the test data, which indicates that the modified Chaboche damage model can precisely describe the accumulated damage in TC25 titanium alloy at high cycle fatigue under unaxial loading. Finally, the high cycle fatigue lifetimes for TC25 titanium alloy specimens at different strain hardening rates are tested at a given stress ratio of 0.1, the effect of strain hardening on fatigue life is investigated based on a microstructure analysis on TC25 titanium alloy, and an expression between fatigue life and strain hardening rate is derived

Sign in / Sign up

Export Citation Format

Share Document