Fatigue Damage Characteristics Considering the Difference of Tensile-Compression Modulus for Asphalt Mixture

Wave induced vibrations often referred to as springing and/or whipping increase the fatigue and extreme loading in ship hull girders. Both effects are disregarded in current ship rules. Various numerical codes exist for predicting the wave induced vibrations, but so far they are not considered reliable. Another means to investigate the importance of the high frequency response, although more resource demanding, is to carry out full scale measurements and/or model tests. Recently, full scale measurements of blunt ships have been carried out by DNV, and in this paper one of these ships was considered and tested in a towing tank to evaluate the additional fatigue damage due to the wave induced vibrations. Different excitation sources may excite the 2-node vertical vibration mode depending on ship design, and it is not straight forward to determine which is more important. The relative importance of the excitation mechanisms are investigated by two approaches in this paper. The first approach separates the whipping from springing to illustrate their relative importance based on basic theory in combination with model test results. The linear and second order transfer functions are utilized in this procedure. The second approach deals with the effect of the bow design on the additional fatigue damage. Three different bows were tested. The first bow design is identical to the real ship. The second bow design is a simplified version of the first one, by removing the bulb and flare. The third bow is fundamentally different from the two former blunt bows. Bow three is sharp pointed with a vertical sharp stem and vertical ship sides. The results indicate that the importance of whipping depends on the sea state, but that it is of similar importance as springing for the sea states that contributes most to the fatigue damage. Moreover, the difference in the additional fatigue damage due to wave induced vibrations for different bow shapes is moderate. This indicates that vessels with pointed bows and without pronounced bow flare, such as LNG vessels, may have a similar contribution from wave induced vibrations. Modern container vessels, which are more slender, but with pronounced bow flares should be further investigated.

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Energy dissipation approach to quantify the fatigue damage of glass fibre grid inlaid asphalt mixture

Advances in Materials and Pavement Performance Prediction II ◽

10.1201/9781003027362-75 ◽

2020 ◽

pp. 320-323

Author(s):

Arbin Raj ◽

B.S. Abhijith ◽

J. Murali Krishnan

Keyword(s):

Energy Dissipation ◽

Fatigue Damage ◽

Glass Fibre ◽

Asphalt Mixture

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Fatigue Damage Characteristics of Deformable Mirrors for Wavefront Correction

Chinese Journal of Lasers ◽

10.3788/cjl201643.1105002 ◽

2016 ◽

Vol 43 (11) ◽

pp. 1105002

Author(s):

陈丽霞 Chen Lixia ◽

胡小川 Hu Xiaochuan ◽

张彬 Zhang Bin ◽

孙年春 Sun Nianchun

Keyword(s):

Fatigue Damage ◽

Deformable Mirrors ◽

Wavefront Correction ◽

Damage Characteristics

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Testing Study on Fatigue Damage of Asphalt Mixture with Considering the Restoration Time

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.505-506.204 ◽

2014 ◽

Vol 505-506 ◽

pp. 204-209

Author(s):

Biao Ding ◽

Chuan Chao Zheng ◽

Hua Nan Wang

Keyword(s):

Fatigue Damage ◽

Cyclic Load ◽

Asphalt Mixture ◽

Sharp Decrease ◽

Dissipated Energy ◽

Time Interval ◽

The Road ◽

Restoration Time ◽

Cumulative Dissipated Energy ◽

On The Road

Conventional fatigue damage test of asphalt mixture is usually under the condition of constant stress-mode or strain-mode, the specimen is broken when the cyclic load reaches certain number of times. In fact, vehicles on the road are not continuous, traffic volume is different in different time, there is a time interval between neighbouring vehicles. In this paper, time interval was set between two neighbouring cycles, the effect of recovery way, strain size and temperature on cumulative dissipated energy were analyzed. The results show that: in the early stages, recovery methods have little impact on the cumulative dissipated energy, with the increase of cyclic number, the value of trabecular under unconstrained condition will be greater than that of trabecular under constrained one. The bigger the strain size, the greater the value of cumulative dissipated energy; The lower the temperature, the greater the value of cumulative dissipated energy. Under the conditon of low strain size or high temperature , the value of cumulative dissipated energy decreases linearly. For the high strain or low temperature, there is a sharp decrease between the first cycle and second cycle, and then decreases linely in the later cylcles.

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CHARGE DENSITY DIFFERENCES AND THE NUCLEAR INCOMPRESSIBILITY

Modern Physics Letters A ◽

10.1142/s0217732386000646 ◽

1986 ◽

Vol 01 (09) ◽

pp. 509-515 ◽

Cited By ~ 4

Author(s):

J. BARTEL ◽

G. WENES ◽

M. WAROQUIER ◽

J. RYCKEBUSCH

Keyword(s):

Nuclear Matter ◽

Charge Density ◽

Level Density ◽

Mean Field ◽

Compression Modulus ◽

Charge Density Distribution ◽

Effective Interactions ◽

Pairing Correlations ◽

The Difference ◽

Nuclear Incompressibility

The influence of the nuclear matter compression modulus K∞ on the difference in the charge density distribution of 208 Pb −206 Pb is investigated in a self-consistent mean field approach with a variety of density dependent effective interactions of the generalized Skyrme type. It is found that in addition to a dependence on the compressibility associated with a given Skyrme force the results also depend strongly on the pairing correlations which, through the level density, are influenced by the nuclear matter effective mass.

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Complexities of Crosslink Density in Filled Elastomers

Rubber Chemistry and Technology ◽

10.5254/1.3535619 ◽

1965 ◽

Vol 38 (1) ◽

pp. 123-133 ◽

Cited By ~ 5

Author(s):

K. E. Polmanteer ◽

J. D. Helmer

Keyword(s):

Crosslink Density ◽

Diatomaceous Earth ◽

Volume Fraction ◽

Mathematical Expression ◽

Compression Modulus ◽

Dynamic Mechanical Properties ◽

Fume Silica ◽

Wet Process ◽

Siloxane Polymers ◽

The Difference

Abstract This work was undertaken to learn more about the complicated role of fillers in reinforcing siloxane polymers and attempt to clarify why silica fillers cause the crosslink density to increase significantly more in siloxane polymers than in hydrocarbon polymers. To carry out this study it was necessary to decide upon a method for determining the effective number of crosslinks. A simple mathematical expression applicable to both filled and unfilled elastomers was developed for use with a compression modulus technique for swollen vulcanizates. The fillers studied with polydimethylsiloxane (containing a small amount of methylvinylsiloxane) were a fume silica, wet process silica, diatomaceous earth, and two ground quartz silicas. The effect of concentration of network chains on tensile strength, modulus, and dynamic mechanical properties was compared for fume silica and diatomaceous earth filled stocks. All of the types of silica studied caused the crosslink density to increase several times over that of the unfilled vulcanizate. This may be contrasted with a factor of less than 2 for a filled (carbon black or silica filler) hydrocarbon polymer. The difference in behavior of the two polymer systems was attributed to a pronounced interaction between the siloxane polymer and the silica surface. The data indicated that filler structure has a more pronounced effect on crosslink density than surface area. It was found that the log of concentration of network chains gives a straight line when plotted as a function of volume fraction filler.

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Effect of Extended Aging on Asphalt Materials Containing Re-Refined Engine Oil Bottoms

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2632-07 ◽

2017 ◽

Vol 2632 (1) ◽

pp. 60-69 ◽

Cited By ~ 11

Author(s):

David J. Mensching ◽

Adrian Andriescu ◽

Christopher DeCarlo ◽

Xinjun Li ◽

Jack S. Youtcheff

Keyword(s):

Low Temperature ◽

Fatigue Testing ◽

Asphalt Mixture ◽

Field Performance ◽

Cyclic Fatigue ◽

Engine Oil ◽

Short Term ◽

Bending Beam Rheometer ◽

The Difference

The use of re-refined engine oil bottoms (REOBs) in asphalt pavements is a topic of much debate because the aging susceptibility and quantity of the additive in the binder may affect field performance. In this study, four mixtures with varying REOB contents (up to 15%) were long-term oven aged by using a high-temperature, short-duration method (135°C, 24 h) and compared with existing data on mixtures aged with more conventional short-term and long-term oven-aging procedures. The recovered binders underwent Superpave® grading, double-edge notched tension, and extended bending beam rheometer testing, and the binders were subjected to dynamic modulus, cyclic fatigue testing in the asphalt mixture performance tester, and thermal stress restrained specimen testing. Results showed a general insensitivity when short-term oven-aged (135°C, 4 h) materials were compared with long-term oven-aged (85°C, 5 days) materials, whereas the aging process at 135°C over 24 h resulted in substantial changes to the stiffness and relaxation properties across high-, intermediate-, and low-temperature modes. The difference between the stiffness-based and slope-based low-temperature performance grades appears to be an indicator for REOB modification, with the test for physical hardening of the binder being more sensitive than standard bending beam rheometer testing. The details in this paper provide information for the asphalt pavement community to consider as specifications. Standard practices are developed to address REOB modification.

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Rutting and Fatigue Performance Evaluation of Qingchuan Rock Modified Asphalt Mixture

The Open Construction and Building Technology Journal ◽

10.2174/1874836801610010450 ◽

2016 ◽

Vol 10 (1) ◽

pp. 511-523 ◽

Cited By ~ 1

Author(s):

Li Limin ◽

He Zhaoyi ◽

Liu Weidong ◽

Hu Cheng ◽

Liu Yang

Keyword(s):

Fatigue Damage ◽

Resilient Modulus ◽

Asphalt Pavement ◽

Asphalt Mixture ◽

Fatigue Performance ◽

Raw Material ◽

Loading Test ◽

Modified Asphalt ◽

Tensile Fatigue ◽

Dynamic Creep

To solve the problem of rutting and fatigue damage to asphalt pavement, rutting and fatigue performances of Qingchuan rock asphalt modified asphalt were studied, based on the dynamic shear rheometer test, the dynamic creep test, the rutting test, the indirect tensile fatigue test, the small-sized acceleration loading test, the compressive resilient modulus test, the BISAR3.0 Program and the rutting calculation method based on dynamic finite element method. The results indicate that Qingchuan rock asphalt modifier can obviously improve the anti-fatigue performance and anti-rutting performance of asphalt pavement. Taking the anti-rutting performance and the raw-material price of asphalt into consideration, a rock asphalt optimum content ranging from 5% to 8% is suggested. Qingchuan rock asphalt is a good modifier to solve the rutting and the fatigue damage of asphalt pavement.

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DAMAGE CHARACTERISTICS OF RECYCLED ASPHALT MIXTURES UNDER THE EROSION EFFECT OF SNOW-MELTING SALT

DYNA INGENIERIA E INDUSTRIA ◽

10.6036/10174 ◽

2021 ◽

Vol 96 (4) ◽

pp. 379-387

Author(s):

Baoyong Xue ◽

Ping Yao ◽

Xiaolong Zou ◽

Qian Liu ◽

Yanlong Zhao

Keyword(s):

Asphalt Pavement ◽

Water Immersion ◽

Asphalt Mixture ◽

Snow Melting ◽

Freezing And Thawing ◽

Recycled Asphalt ◽

Damage Characteristics ◽

Splitting Strength ◽

Damage Degree ◽

Erosion Effect

The erosion effect of snow-melting salt will degrade the durability of recycled asphalt pavement, but the damage characteristics of recycled asphalt mixture triggered by the erosion effect of snow-melting salt remain unclear. To solve the snow-melting salt-induced durability degradation of asphalt pavement, two commonly used snow-melting salts, NaCl and CaCl2, were selected to carry out the saline water immersion, salt-drying and -wetting cyclic and salt-freezing and -thawing cyclic splitting tests on recycled asphalt mixture, and the attenuation laws of splitting strengths and its damage characteristics under the erosion effect of snow-melting salts were analyzed. Results demonstrate that with the increase in soaking time, salt-drying and -wetting cycles and salt-freezing and -thawing cycles, the splitting strength of the recycled asphalt mixture maintain a declining trend, and the attenuation rate of splitting strength is elevated. The damage degree of the recycled asphalt mixture presents a nonlinear growth trend during saline water immersion, salt-drying and -wetting cycles, and salt-freezing and -thawing cycles. Under the same conditions, the damage degree after the action of NaCl solution is higher than that after the action of CaCl2 solution, and meanwhile, within the range of test concentration, the damage degree after the action of low-concentration saline solution is higher than that after the action of high-concentration saline solution. Conclusions provide a significant reference for the composition design and maintenance decisions of recycled asphalt pavement materials in cold regions. Keywords: road engineering; salt erosion; recycled asphalt mixture; damage characteristics; splitting strength

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