Increase Of Loading Time Research Articles

Creep fatigue interaction at high temperature in C630R ferritic/martensitic heat-resistant steel

The study investigated the creep-fatigue interaction behavior, fracture mechanism, and microstructure evolution of C630R ferritic/martensitic heat-resistant steel at 630 °C and 1% strain amplitude. The results indicate that C630R ferritic/martensitic heat-resistant steel exhibits noticeable cyclic softening behavior, with a decrease in the softening ratio from 0.46 to 0.40 as loading time increases. Microstructure evolution was examined using optical and scanning electron microscopes, revealing the appearance of secondary cracks on the longitudinal section of the sample. These cracks exhibited a curved expansion trend with multiple deformations and highly bifurcated micro-cracks at a low loading time of 30s. However, when the load holding time was increased to 300s, the fatigue cracks tended to expand in a straight line with fewer branches. Furthermore, the observed crack growth path under different loading times showed enrichment in Fe and Cr, with the crack tip containing Cr oxide, which helped prevent fatigue crack propagation. As the loading time increases, the rise in crack closure resulting from oxidation leads to a decrease in crack propagation. Electron backscatter diffraction observation revealed the formation of numerous substructures and recrystallized grains after varying holding times, enhancing the material's resistance to crack propagation. Moreover, the study found that with increasing load dwell time, the deformed grains decreased, and substructural grains became dominant (57.68% and 62.77% under 30s and 300s, respectively). This increased crack resistance resulted in shorter secondary cracks under prolonged load retention, with the secondary crack length decreasing from 146.36 μm at 30s loading time to 109.09 μm at 300s loading time. Additionally, the kernel misorientation angle value decreased significantly after different loading times, leading to a higher likelihood of cracks or holes forming in regions with high KAM values, where low-angle grain boundaries were formed.

Temporal evolution of fracture transport properties of fractured shales during long-term stress compaction

Understanding the temporal evolution of fracture transport properties in shales is of increasing importance for the long-term safe operation of many underground engineering projects. Here, a series of long-term (60 days each) water seepage and gas breakthrough experiments utilizing three shale samples, each with a single artificial fracture, was conducted to evaluate the time-dependent evolution of permeability and gas breakthrough pressure (GBP) under constant confining stress. Our results show continuous decreases in permeability and increases in GBP with time, and the rate of change in both is initially rapid but then slows. As the loading time increases, the permeabilities and GBPs become relatively constant. The inferred mechanisms are aperture reductions caused by mechanical creep and clay swelling of fractures. Pretest and posttest scans of fracture surfaces reveal some changes in asperity height, which demonstrates the occurrence of mechanical damage to the fracture during the experiments. Long-term stress compaction causes flow channels to narrow or even partially close over time. The fluid flow in confined fracture is controlled by some narrow apertures in the flow channels, which act as bottleneck points. The apertures at these points decrease to the micro-nano level under stress, significantly reducing fracture transport properties. While the fracture transport properties of fractured shale obviously decrease during long-term stress compaction, residual fracture voids still dominate the fluid flow over a longer period, and are especially prone to gas escape.

Study on dynamic characteristics and non-constant fractional dynamic creep model for frozen silty clay

The long-term dynamic characteristics of frozen soil are important theoretical basis for the dynamic stability evaluation of geoengineering in cold regions. Compared to unfrozen soil, the dynamic creep behaviour is more complicated owing to its rheological property. In this study, triaxial tests under cyclic loads with different constant stress amplitudes and confining pressures for frozen silty clay (FSC) are carried out. The long-term dynamic creep process and deformation mechanism under different dynamic stress amplitudes were investigated. The test results show that with the cyclic numbers increasing, the dynamic elastic modulus and the hysteretic loop area decrease because of the damage accumulation in the samples. Also the dynamic strength decreases with an increase in failure cyclic numbers under different confining pressures. Based on the fractional calculus theory, replacing the Newton's dashpot in the traditional Maxwell model with fractional Abel's dashpot, a fractional dynamic creep model is established. Considering the melting and crushing of the ice inclusion, the slip effect in frozen soil is increasingly significant, the viscosity coefficient of dashpot element is decreasing with an increase in loading time. In the proposed model, a non-constant dashpot element is introduced to clarify the constitutive relation of the FSC in the accelerated creep stage. The comparison results confirm that the proposed constitutive model is valid and suitable for reflecting the long-term dynamic creep behaviours of the FSC.

Study on developing a multi-integrated textile system: investigating the liquid loading and release performances of hollow fiber yarns

Textile fabrics have a long history of use for a wide range of applications that satisfying the needs of livelihood. In this era of modernization and high technological advancements, the use of textiles has spread to include using man-made and nonconventional textiles. Among them, hollow fiber-based textiles have great application prospects due to their high surface-area-to-volume ratio, high loading capability, high active surface area and high permeability of the porous layer. Herein, the liquid loading and release performances of various hollow fiber yarns with different parameters (i.e. spinning methods, yarn count, loading amount, releasing rate, etc.) under optimized negative pressure are presented. Results showed that the hollow fiber vortex spun yarn (with yarn count Ne 10/1) had the highest loading ability under negative pressure. Moreover, the amount of liquid loaded into the yarns first increased rapidly and then the rate became slower with an increase of loading time and finally tended to a stable value. In addition, as the release time increases, the amount of liquid released from the hollow fiber yarns became higher and the release rate became lower. These findings provide an important foundation for the development of the multi-integrated textile system, which is comprises the controllable loading and delivery of various types of active substances and chemicals.

Percolation and Supply Behavior of Lubricant on Porous Self‐Lubricating Material

This article aims to investigate the percolation and supply behavior of lubricant on the porous self‐lubricating material. The numerical model is established to describe the infiltration‐exudation response in the deformed porous material. It is found that the lubricant stored in the pores is forced to flow when the loaded porous matrix deforms. The flow drives the seepage stratification in the porous body and forms an interlayer flow zone. The fluid pressure gradient in the normal direction is the internal factor of the seepage stratification. The interlayer flow zone first appears in the middle of the vertical direction of the porous matrix. With the increase of loading time, the interlayer flow zone gradually moves from the middle to the bottom of the porous matrix, which means that the quantity of the lubricant stored in the porous surface decreases. In the whole process of the seepage response, the lubricant flows out from the inlet and continuously supplies lubricant to the contact area. Delaying the downward movement of the interlayer flow zone can ensure the continuous exudation of the lubricant, which is beneficial to maintain excellent lubrication characteristics.

Experimental investigation on the deformation and strength properties of cemented gangue backfill column under long-term axial compression

To reveal the time-dependent deformation and the effect of loading history from early curing age on mechanical properties of cemented gangue backfill column (CGBC) under long-term axial compression in constructional backfill mining, the step-by-step load was adopted to simulate the loading history of the roof before 28d and then enter the long-term creeping stage, and the uniaxial compressive strength and elastic modulus of samples after 360d loading were tested. Four initial loading ages (ILA) and four stress-strength ratios (SSR) were set to simulate the actual loading conditions. The time-dependent damage process of CGBC was monitored by ultrasonic and electrical resistivity equipment. The results show that: the strain of CGBC increases with the increase of loading time and SSR; the earlier the ILA is, the higher the total strain shows, but the smaller the creep strain after 28d will be. The loading history at early curing age increases the compactness of CGBC and promotes the cement hydration process, and decreases the deformation after 28d. The final strength and elastic modulus of the long-term loading samples are larger than those of the control ones, and increase first and then decrease with SSR 60% and ILA 7d as the turning point, and the most increase reaches 33% and 82%, respectively. The CGBC can keep long-term stability at 80% SSR. The competition of compaction, healing and damage of CGBC under different SSRs at early curing age determines the final mechanical properties. Ultrasonic pulse velocity and resistivity of CGBC increase with the increase of time and are also affected by the SSR. A rheology-based model that considered the time-hardening of CGBC at early curing age was proposed to predict the time-dependent deformation of CGBC starting from early age. The results could be used to guide the design of CGBC and deformation prediction of the roof.

Study on the thermal transient of cathode catalyst layer in proton exchange membrane fuel cell under dynamic loading with a two-dimensional model

• A two-dimensional, two-phase, PEMFC transient thermal model is established. • Effects of operating&structure parameters on CCL thermal transient are studied. • CCL temperature overshoot and fluctuation are analyzed under dynamic loading. • Both electrochemical and two-phase flow transients cause temperature overshoot. • Optimal loading rate, operating temperature, and width ratio are suggested. The temperature variation of the cathode catalyst layer (CCL) inside the proton exchange membrane fuel cell (PEMFC) caused by dynamic loading will damage the material and consequently shorten cell lifetime. To address this problem, the thermal transient of CCL needs to be clarified first before further action is taken. In this work, the effects of current load, operating temperature, and channel to rib width ratio on the thermal transient of CCL are systemically investigated by a two-dimensional, two-phase transient PEMFC thermal model. At the same time, the action mechanisms of electrochemical and two-phase flow transients on the thermal transient are detailly described. We observe that the overshoot of CCL temperature will happen as the current steps from nearly zero to a certain level. Interestingly, under the action of local water and thermal evolution, the overshoot amplitude first increases and then decreases with the rise of the step current density. Moreover, with the increase in loading time and operating temperature, temperature overshoot significantly decreases. The former is attributed to the quasi-steady state operation of two-phase flow at a long loading time, while the latter is caused by the reduction of membrane water absorption with atmosphere drying. It is also found that the larger channel to rib width ratio will induce more uniform temperature fluctuation in CCL regions under rib and channel due to the more uniform electrochemical reaction caused by shorter O 2 transport path length. The above model simulation results can guide cell operation and design for better thermal management under dynamic loading.

Regional Characteristics of Deformation and Failure of Coal and Rock under Local Loading

Abstract The deformation regional characteristics and fractal characteristics of crack propagation in raw coal and briquette coal under local loading were studied. The results show that the stress-strain curves of the two samples under local loading have typical stage characteristics, the deformation of the raw coal samples in the compaction stage is greater than that of the briquette coal samples, and the peak strength of the two samples increases linearly with the increase of the loading area. With the increase of loading time, the strain of the nonloading zone shows a slow growth stage and a strain stable stage. The farther away from the loading area, the smaller the strain and the strain rate are. Under local loading, the relation of the fractal dimension of the raw coal surface and strain can be described as a cubic function, while the relation can be expressed by a quadratic function for the briquette sample, and the relation of the fractal dimension and loading area of the raw coal and briquette both can be described as a quadratic function. Under uniaxial compression, the briquette coal mainly undergoes tensile failure, and the raw coal mainly undergoes x-type shear failure. Under local loading, the raw coal and briquette coal microcracks started propagation from the easy fracture zone, and the main control crack is located in the interface between the loading zone and the nonloading zone.

Estimation of Wear Resistance for Multilayer Coatings Obtained by Nitrogenchroming

This article deals with improving the wear resistance of multilayer coatings as a fundamental problem in metal surface treatment, strengthening elements of cutting tools, and ensuring the reliability of machine parts. It aims to evaluate the wear depth for multilayer coatings by the mass loss distribution in layers. The article’s primary purpose is to develop a mathematical method for assessing the value of wear for multilayer steel-based coatings. The study material is a multilayer coating applied to steel DIN C80W1. The research was performed using up-to-date laboratory equipment. Nitrogenchroming has been realized under overpressure in two successive stages: nitriding for 36 h at temperature 540 °C and chromizing during 4 h at temperature 1050 °C. The complex analysis included several options: X-ray phase analysis, local micro-X-ray spectral analysis, durometric analysis, and determination of wear resistance. These analyses showed that after nitrogenchroming, the three-layer protective coating from Cr23C6, Cr7C3, and Cr2N was formed on the steel surface. Spectral analysis indicated that the maximum amount of chromium 92.2% is in the first layer from Cr23C6. The maximum amount of carbon 8.9% characterizes the layer from Cr7C3. Nitrogen is concentrated mainly in the Cr2N layer, and its maximum amount is 9.4%. Additionally, it was determined that the minimum wear is typical for steel DIN C80W1 after nitrogenchroming. The weight loss of steel samples by 25 mg was obtained. This value differs by 3.6% from the results evaluated analytically using the developed mathematical model of wear of multilayer coatings after complex metallization of steel DIN C80W1. As a result, the impact of the loading mode on the wear intensity of steel was established. As the loading time increases, the friction coefficient of the coated samples decreases. Among the studied samples, plates from steel DIN C80W1 have the lowest friction coefficient after nitrogenchroming. Additionally, a linear dependence of the mass losses on the wearing time was obtained for carbide and nitride coatings. Finally, an increase in loading time leads to an increase in the wear intensity of steels after nitrogenchroming. The achieved scientific results are applicable in developing methods of chemical-thermal treatment, improving the wear resistance of multilayer coatings, and strengthening highly loaded machine parts and cutting tools.

Impacts of load distribution and lane width on pavement rutting performance for automated vehicles

ABSTRACT Over the recent years, considerable attention has been drawn to intelligent driving technologies and particularly to automated vehicles (AVs). The deployment of AVs would provide the opportunity to have more control over the dynamics of the vehicle, including its lateral movement, which can affect the pavement's long-term rutting performance. The controlled lateral movement of the AVs may also imply a reduced lane width. This paper evaluates the impacts of dedicating a reduced lane width to AVs on pavement rutting performance, considering two lateral movement modes for AVs; zero-wander and uniform-wander. A finite element model was developed using ABAQUS software. The rutting simulation results of this study showed that the abrupt changes in the loading schemes of the zero- and uniform-wander modes cause considerable accumulated rutting in the edges of the loading areas. This is significantly greater than the total rutting induced by the human-driven vehicles (HDVs) following the normal-wander mode, which causes a compensated rutting behaviour by a gradual increase in loading time. Furthermore, the comparison between rutting depths in different lane widths reveals that when dedicating the narrower lane for AVs with a uniform-wander distribution, the pavement's total rutting depth would remarkably increase compared to the wider lanes.

Energy-based mechanistic approach for crack growth characterization of asphalt binder

The cohesive cracking within asphalt binders has a significant influence on fatigue cracking resistance of asphalt pavements. To more clearly understand the mechanism and accurately characterize the process of the cohesive cracking occurring within the asphalt binder, an energy-based mechanistic (EBM) approach is applied to determine crack length and the pseudo J-integral is adopted to calculate crack growth rate in this study. First, a critical strain level separating nonlinear viscoelasticity from damage is determined based on a statistical analysis approach, and the result indicates that 0.7% is a critical nonlinear strain level for unmodified asphalt binder. Then, the crack length of asphalt binders is derived based on a torque equilibrium equation and two energy balance equations, as well as crack length is measured and verified based on an image processing method. It is found that contact regions in cracked area of the asphalt binder are formed when performing a strain-controlled rotational shear load. The contact regions have two stages, which first increase to the peak and then decrease with the increase of loading time. Next, the crack growth rate is formulated based on the pseudo J-integral Paris’ law equation considering nonlinear viscoelasticity. A linear relationship between the crack growth rate and the function of material properties (such as shear modulus, phase angle) in double logarithmic scales is proven and experimentally verified. In addition, the Paris’ law parameters (n and A) associated with crack growth rate are determined. Results show that they are independent on strain levels and temperatures. For example, six values of n of the unmodified asphalt binder are approximately equal to 1.10 at 5%, 6%, 7% strain levels when test temperatures are 15°C and 20°C. They are inherent material properties for the asphalt binder.

The Evaluation of the Relationship between Loading Time and Crestal Bone Loss around Dental Implants at 12 Months Control Evaluation after Loading.

The evaluation of the relationship between loading time and crestal bone loss around dental implants 12 months after loading was the objective of this study. All clinical and radiological data of patients treated with posterior mandibular implant-supported fixed dentures between January 4, 2013 and January 3, 2018 were retrieved from the archives. Loading time was recorded as the time between dental implant insertion and loading of the implant-supported restoration. The crestal bone levels of distal and mesial aspects of all implants were measured at postloading 12 months control evaluation on panoramic radiographs. Distal and mesial crestal bone loss values were recorded and averaged to obtain one mean value. The relationship between loading time and crestal bone loss was evaluated with statistical analysis. A total of 89 patients and 238 implants were included in the study. The loading time for each implant was recorded between a range of 0 and 401 days. A linear relationship was observed between loading time and crestal bone loss measured at 12 months control evaluation. The crestal bone loss at 12 months control evaluation after loading was significantly increased with the increase in the loading time after dental implantation (p < 0.05). The range of CBL was narrower between 100 and 200 days of loading time. The increase in loading time may cause increased crestal bone loss after 12 months function. Crestal bone loss at 12 months control evaluation is more predictable in dental implants loaded between 3 to 6 months after dental implant placement.

An Experimental Study on Dynamic Model Groove Under Shock Excitation

Introduction: Variation laws of dynamic response and settlement deformation at different depths of soil roadbed were investigated and summarized in this study through a simulation test with a dynamic model groove in soft clay foundation of low road embankment. Materials and Methods: In this test, the traffic load was simulated by single-point and double-point shock excitation. Besides, loading frequency, intensity and duration were adjusted by a single variable control method. Research results show that peak values of soil pressure and pore water pressure decrease with the increase of buried depth, but they are unrelated to loading intensity and frequency. Conclusion: Nevertheless, settlement deformation does not increase linearly with the increase of frequency or time difference. The accumulative settlement at a depth varies as the loading time increases.

Development and testing of an automated contact plate unit for a cassava grater

Automation has played a vital role, not only in modern industrial processes, but also in agricultural crop processing systems. It is characterized by self-acting machines and devices with integrated control systems that are often arranged in complex industrial processes or systems. This research work was conducted to develop an automated contact plate unit for a cassava grater capable of regulating and enhancing the process of ensuring contact of cassava tubers to the grating surface for efficient and timely grating operation. Fundamental design analysis and calculations were carried out in order to determine and select materials suitable to develop this unit. The major component parts of this system include contact plate, double-acting hydraulic cylinder, hydraulic valve, hydraulic motor, and control system. The results of the performance test using loading time and time sustained by contact plate as operating parameters showed that the lowest grating time of 211 secs was obtained when the system was operated at loading time of 4.40 secs and time sustained by contact plate of 5.85 secs. The optimization of the machine parameters using response surface methodology produced optimum grating time of 258.19 secs with desirability of 90.9% from optimal operating parameters of 4.12 secs of loading time and 10.78 secs of time sustained by contact plate. The time sustained by contact plate has positive significant effects on the grating time. Grating time decreased with increase in loading time and decrease in time sustained by contact plate. The cost of production of the automated system of the contact plate for cassava grater is $ 405.

Strain recovery model for concrete after compressive creep

The research objective of this study is to examine the strain recovery of concrete after compressive creep. First, the influences of concrete strength, load duration, and stress-strength ratio at loading time on the initial-recovery are investigated on 128 concrete prisms. The concrete strength, loading age, and load duration have no clear influence on the initial-recovery strain coefficient (the ratio of initial-recovery strain to initial strain) when the concrete age concrete is over 28 d and load duration is over 41 d, but the initial-recovery strain coefficient decreases as the stress-strength ratio at loading time increases. Moreover, the effects of loading age, load duration, and concrete strength on creep-recovery are investigated by examining data from tests and references. The basic creep-recovery model is obtained by fitting the creep-recovery experimental data from 28 concrete prisms. Then, a multi-coefficient creep-recovery model for concrete that considers the influence of creep, loading age, load duration, and concrete strength is proposed. Finally, the proposed creep-recovery model is verified with reference data, with better performance than the existing creep-recovery models.

Effect of equiaxial tensile strain in early differentiation of mesenchymal stem cells into cartilage cells

To observe the effect of cyclic equiaxial tensile strain in the early differentiation of bone marrow mesenchymal stem cells(BMSCs) into cartilage in mouse under conditions of two-dimensional culture, and to investigate the mechanism of cyclic equiaxial tensile strain in early chondrogenic differentiation. Sixteen KM mouse aged 4 weeks were selected, male and female unlimited, with an average weight of 19.5 g (17 to 21 g). After extracting and isolating the BMSCs from KM mouse, then subculture the BMSCs to the 3rd generation. Seed the cells in the biological plate(BioFlex). According to experimental design, the cells were divided into 6 groups, blank group: ordinary culture medium was cultured for 8 days without isometric cyclic tensile strain stimulation. Control group: chondrogenic differentiation medium was used to culture for 8 days without isometric cyclic tensile strain stimulation. Experimental group: the experimental group was divided into 4 groups, all of which were cultured with chondrogenic differentiation medium for 8 days. During which isometric cyclic tensile strain stimulation was given for 1, 3, 5 and 7 days respectively. At the 8th day, all the cells were collected, the expression of the Sox9, Col-II and ROCK 1 signaling pathway-related molecules was analyzed by RT-PCR. Cells in each group were extracted, and the efficiency of cell proliferation in each group was detected by CCK-8. Glycosaminoglycan content in medium changed last was detected using ELISA. Pericellular matrix was observed by Safranin O staining and Alcian Blue staining. Normal measurement data using mean±standard deviation compared between the blank group and control group using paired t-test, compared between the experimental group and relative group using single factor analysis of variance. (1)After 8 days of culture, compared with the control group, the relative expression of Sox 9 and Col-II mRNA in the experimental group increased gradually with the increase of loading time(P<0.05), while the relative expression of ROCK1 mRNA decreased(P<0.05). Compared with the blank group, the relative expression of ROCK1 mRNA in experimental group and control group increased (P<0.05). (2)With the increase of loading time, the experimental group showed a trend of decreasing at first and then increasing, but compared with the blank group and the control group, the control group decreased significantly. (3)Glycosaminoglycan content in the medium changed last was detected by ELISA. The glycosaminoglycans in the experimental group increased gradually, and the content changes on 7 days loading group were statistically significant compared with other groups(P<0.05). (4)Safranin O and Alcilan staining showed that there was a tendency of cartilage differentiation in the experimental group, and the shape gradually increased with time, which was more obvious than that in the control group; The PCM, Col-II and GAG in the experimental group increased gradually with the increase of mechanical stimulation days, which were more obvious than those in the control group. Under conditions of two-dimensional culture, in the early differentiation of mesenchymal stem cells into cartilage, cyclic equiaxial tensile strain can promote the proliferation of BMSCs and the differentiation into chondrocytes. Moreover, cyclic equiaxial tensile strain may promote chondrogenic differentiation through inhibiting the Rho/ROCK 1 signaling pathway.

Study of EMR and AE during Coal Fracture under Quasi-static Uniaxial Compression Load

A quasi-static uniaxial compression experiment was designed to simulate creep damage in coal. During the experiment, electromagnetic radiation (EMR) and acoustic emission (AE) signals were synchronously acquired. The energy of EMR and AE signals were subsequently calculated after the background noise from the equipment and the environment were filtered out. We then analyzed the change in signal energy associated with the sample strength, loading time and other factors. The results showed that as the loading time increases, the frequency of the periodic signal in the EMR energy also increases. In addition, the dominant AE signal energy release occurs only in the final stage of sample failure. However, intermittent AE pulse clusters were recorded during the entire loading cycle. The analysis of data provided a strong correlation between the change in the AE signal energy and the expansion of micro-cracks in the materials, which is manifested as an irreversible deformation of the material at the macroscopic scale.

Study on Creep Characteristics and Constitutive Model for Thalam Rock Mass with Fracture in Tunnel

In the each loading stage, strain and creep strain occurs instantaneously on the axial and lateral of fractured. Instantaneous strain leads to the 80% overall specimen deformation. The axial strain is about 2–3 times larger than the lateral strain. Instantaneous strain completed time and deformations under each loading stage decrease when the loading time increases. With the increasing of loading, axial strain and lateral strain of fractured phyllite present the approximate linear curve growth change. With increasing of axial stress, the relationship between the lateral strain and axial strain transform from the linear increased trend to the index increased trend. With the increasing of moisture content, the axial deformation and lateral deformation of fractured phyllite increase. The curves of axial strain and lateral strain under soaked for 10 and 15 days condition are similar. The modified Burgers model can describe each creep stage of fractured phyllite which have high fitting precision, less fluctuation and high reliability. Therefore, modified Burgers model can provide an effective way to analyze the creep characteristics of fractured phyllite.

Investigation of the excess pore water pressure inside compacted asphalt mixture by dynamic triaxial tests

Moisture damage is one of the major problems in asphalt pavements. The pore water in asphalt mixture pavements is easily evolved into excess pore water pressure under the action of the traffic load. According to the reverse fluid-solid coupling theory, the excess pore pressure of water damages the asphalt film or mastic on the aggregate surface, which results in splitting at the contact points among aggregates. Further, this excess pore water pressure scours, emulsifies, and strips the asphalt film surrounding the aggregates. Therefore, many problems occur in asphalt pavements. In this study, the excess pore water pressure of the compacted asphalt mixture was investigated by dynamic triaxial tests (DTT). The results show that with the increase of loading time, the excess pore water pressure has three typical stages. At the same time, the deviator stress and loading frequency both influence the peak value of the excess pore water pressure. The higher the deviator stress is, the greater the peak value of the excess pore water pressure is. Similarly, the bigger the loading frequency is, the greater the peak value of the excess pore water pressure is. These conclusions show that overloaded vehicles and high traffic capacity are the external influential factors of moisture-induced damage to asphalt mixtures.

赤血球“カメレオン効果”

We found a new phenomenon of changing RBC color and named it "Chameleon Effect". When a RBC is compressed in a construction channel, the RBC dramatically changes its transparency level with the increase of loading time. Since it is well known that there are close relationships between diseases and the deformability of RBC, we focused on the correlation between this phenomenon and deformability. We experimentally show that the loading contributes to changing the mechanical impedance. In addition, we also examined the “Chameleon Effect” precisely and showed that this effect strongly correlates with the dynamic behavior of RBCs during shape recovery.