scholarly journals Influence of Real-Time Heating on Mechanical Behaviours of Rocks

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bin Gu ◽  
Zhijun Wan ◽  
Yuan Zhang ◽  
Yangsheng Ma ◽  
Xiaodong Bernard Xu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Real Time ◽  
Heating Temperature ◽  
Thermal Cracking ◽  
Effect Of Temperature ◽  
Rock Engineering ◽  
Mechanical Behaviours ◽  
Theoretical And Numerical Analysis ◽  
Rock Mechanical Properties

The rock mechanical properties under the effect of high temperature present a great significance on underground rock engineering. In this paper, the mechanical properties of sandstones, marbles, and granites under real-time heating were investigated with a servo-controlled compression apparatus. The results show that mechanical behaviours of all the three types of rocks are influenced by real-time heating to different degrees. Due to thermal cracking, the uniaxial compressive strengths decrease as the heating temperature rises from room temperature to 400°C. Above 400°C, the sandstone exhibits a significant increase in UCS because of the sintering reaction. The sintering enlarges the contact area and friction between crystal grains in the sandstone, which strengthens the bearing capacity. For marbles, the UCS continues to decrease from 400°C to 600°C due to thermal cracking. However, the carbonate in the marble begins to decompose after 600°C. The generated particles would fill the cracks in the marble and increase the strength. For granites, their UCS presents a sharp decline after 400°C because of thermal cracking. For all rock elastic modulus, they present a decreasing trend, and this indicates that the rock’s ability to resist deformation gradually weakens under the effect of temperature. In general, rock mechanical behaviours under real-time heating differ from those in normal situations, and use of the parameters presented here is important for underground rock engineering related to high temperature and can improve the precision in theoretical and numerical analysis.

Experimental Study on the Strength and Deformation Quality of Granite with Effect of High Temperature

2012 ◽  
Vol 226-228 ◽  
pp. 1275-1278 ◽  
Author(s):  
Xiao Li Xu ◽  
Feng Gao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
High Temperature ◽  
Reference Value ◽  
Effect Of Temperature ◽  
Rock Crystal ◽  
Brittle Ductile Transition ◽  
Strength And Deformation ◽  
Temperature Strain

Experiments on granite under uniaxial compression at high temperature of 25~850°C and after high temperature of 25~1300°C were conducted to study the effect of temperature on rock strength and deformation quality. The results show that: (1) Fitting curves between temperature strain and thermal expansion coefficient with temperature are closely first order growth exponential function relation at high temperature. Temperature strain has mutagenicity after high temperature, which can not reflect rock deformation law at high temperature exactly. (2)Mechanical properties of granite weak continuously at high temperature. Compressive strength and elastic modulus show second order attenuation trend of exponential law. But mechanical properties show mutation state after high temperature, which is closely related to the alteration of rock crystal form and brittle-ductile transition. Regression curves between compressive strength and elastic modulus with temperature are closely polynomial curve. The results reflect the fundamental regulation of granite’s interior structure changing under the action of different temperature, which will provide some reference value to rock engineering involved in high temperature.

Study on the Mechanism of Woven Cotton Fabric during Steam Ironing

2015 ◽  
Vol 671 ◽  
pp. 179-185 ◽  
Author(s):  
Fan Wu ◽  
Shuai Tong Liang ◽  
Xue Mei Ding
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Physical And Mechanical Properties ◽  
Cotton Fabrics ◽  
Temperature Treatment ◽  
Woven Fabrics ◽  
Effect Of Temperature ◽  
High Temperature Treatment ◽  
Recovery Rates ◽  
Basic Parameters

Cotton fabrics are very popular textile products to consumers due to their soft hand and comfortable wearing performance. However, the severe wrinkles on cotton fabrics will frequently happen after washing or wearing. As the growth of the market and demand of consumers, the sales of the steam ironing machine which can remove wrinkles to some extent is getting better. At present, the research is inadequate on the wrinkling mechanism during steam ironing. Therefore, in this paper, we aimed to investigate how cotton woven fabrics’ performance influences on the smoothness appearance after steam ironing. To further analyze wrinkling mechanism, fabrics’ wrinkle recovery rates which comprehensive characterize the physical and mechanical properties were tested with PhabrOmeter, including wrinkle recovery rates at normal temperature and after high temperature treatment. Then, the effect of temperature to fabrics’ wrinkle recovery rates and its relationship with fabrics’ smoothness appearance after ironing were studied. The results indicate that there are no significant correlations between the fabric basic parameters with smoothness appearance after ironing. The effect of temperature during ironing can improve the wrinkle recovery rates about 6%-21%. And no significant correlation is showed between smoothness appearance after ironing and wrinkle recovery rates. Keywords: Steam Ironing; mechanism; fabric parameters; wrinkle recovery rate.

scholarly journals HIGH TEMPERATURE OXIDATION OF TI-6AL-4V ALLOY FABRICATED BY ADDITIVE MANUFACTURING. INFLUENCE ON MECHANICAL PROPERTIES

2020 ◽  
Vol 321 ◽  
pp. 03006
Author(s):  
Antoine CASADEBAIGT ◽  
Daniel MONCEAU ◽  
Jonathan HUGUES
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Additive Manufacturing ◽  
Titanium Alloys ◽  
Oxidation Kinetics ◽  
High Temperature Oxidation ◽  
Effect Of Temperature ◽  
Premature Failure ◽  
Temperature Oxidation

Titanium alloys, such as Ti-6Al-4V alloy, fabricated by additive manufacturing processes is a winning combination in the aeronautic field. Indeed, the high specific mechanical properties of titanium alloys with the optimized design of parts allowed by additive manufacturing should allow aircraft weight reduction. But, the long term use of Ti-6Al-4V alloy is limited to 315 °C due to high oxidation kinetics above this temperature [1]. The formation of an oxygen diffusion zone in the metal and an oxide layer above it may reduce the durability of titanium parts leading to premature failure [2, 3]. In this study, Ti-6Al-4V alloy was fabricated by Electron Beam Melting (EBM). As built microstructure evolutions after Hot Isostatic Pressure (HIP) treatment at 920 °C and 1000 bar for 2h were investigated. As built microstructure of Ti-6Al-4V fabricated by EBM was composed of Ti-α laths in a Ti-β matrix. High temperature oxidation of Ti-6Al-4V alloy at 600 °C of as-built and HIP-ed microstructures was studied. This temperature was chosen to increase oxidation kinetics and to study the influence of oxidation on tensile mechanical properties. In parallel, two other oxidation temperatures, i.e. 500 °C and 550°C allowed to access to the effect of temperature on long-term oxidation.

Mechanical properties of granite under real-time high temperature and three-dimensional stress

2020 ◽  
Vol 136 ◽  
pp. 104521
Author(s):  
Xiao Ma ◽  
Guiling Wang ◽  
Dawei Hu ◽  
Yanguang Liu ◽  
Hui Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Real Time ◽  
Three Dimensional

Experimental Evaluation of Abradable Seal Performance at High Temperature

2008 ◽  
Author(s):  
A. Dadouche ◽  
M. J. Conlon ◽  
W. Dmochowski ◽  
B. Liko ◽  
J.-P. Bedard
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Gas Turbines ◽  
Operating Temperature ◽  
Microstructural Analysis ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Gas Leakage ◽  
Series Of Experiments ◽  
Aero Engines

Abradable seals have been used in aero-engines and land-based gas turbines for more than three decades. They are applied to various sections of the engine in order to reduce gas leakage by optimizing the gap between rotating and stationary parts. This optimization represents a significant increase in efficiency and decrease in fuel consumption. Performance evaluation of any abradable seal includes measurement of its mechanical properties, abradability tests and (ultimately) tests in engines. The aim of this paper is to study the effect of temperature on the rub performance of abradable seals. A series of experiments has been carried out in order to evaluate a commercially available seal material at different operating conditions. The effect of operating temperature on contact force, abrasion scar appearance and blade wear is examined and analyzed. A microstructural analysis of the rub scar has also been performed.

Successful Drilling Campaign of High Angled Wells in Tight Gas Fields using 3D Geomechanical Modeling and Real-Time Monitoring

2021 ◽  
Author(s):  
Salim Al-Busaidi ◽  
Qasim Hinaai ◽  
Rajeev Ranjan Kumar ◽  
Ying Ru Chen ◽  
Redha Hasan Al Lawatia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Real Time ◽  
Shear Failure ◽  
Horizontal Stress ◽  
Strike Slip ◽  
Size Analysis ◽  
Reverse Fault ◽  
Core Data ◽  
Geomechanical Analysis ◽  
Rock Mechanical Properties

Abstract The field under study is witnessing an increasing trend in NPT events while drilling vertical wells through high stressed shale formations and the underlying depleted sandstone reservoir in the same section. The field has multiple sets of faults with lateral variations in stress azimuth and completion quality with the regional strike-slip regime. High angled wells are being planned to increase reservoir coverage and perform hydro fracturing. This paper provides details of capturing stress regime variation along with the effects of depletion in offset wells and identify suitable azimuth of planned well with drilling risks through a 3D geomechanical study. Comprehensive 1D mechanical earth models are constructed using open hole logs, core data and available hydro-fracturing results for wells in the field. Rock mechanical properties have been calibrated at well scale as per core data. Poro-elastic horizontal strain method at well scale indicates a strike-slip to reverse fault variation with significant horizontal stress anisotropy as evident from the closure pressure range of 9,500 psi to 12,500 psi. 3D numerical geomechanical model has been constructed considering structural discontinuities, rock mechanical properties and formation pressure to estimate the principal stresses. Stress direction data from dipole sonic measurements and breakout azimuth from borehole image logs are used for calibration in 3D model incorporating faults. Stress path for depletion has been estimated. Results from the study suggested change in casing policy specifically to have a liner isolating the overburden formations where more than 800 m should be drilled prior to entering the depleted reservoir formation. 3D geomechanical analysis reckons that the mud weight should be in the range of 12.7 kPa/m to 13.1 kPa/m during building up the well profile at 80 deg inclination in overlying shale while 1D study suggesting a range of 13.2 kPa/m to 13.7 kPa/m. Along well path at 80deg to 90deg deviation within reservoir layer toward minimum horizontal stress azimuth, mud weight requirement was found to be much lower at 11.5 kPa/m to 12.1 kPa/m. Apart from mud weight, BHA and chemicals were optimized to avoid differential sticking and better hole cleaning for respective sections. Actual mud weight used was in the range of 12.8 kPa/m to 13.1 kPa/m for building up with no torque and drag issue while running liner and BHA trips. Mud weight was maintained in the range of 11.5 kPa/m to 11.8 kPa/m in the horizontal section with minimum breakouts and smoother hole condition. Cuttings shape and size analysis were performed regularly to check well behavior and manage downhole pressure higher than shear failure limit. Using 3D Geomechanical study and continuous monitoring of drilling parameters in near real-time, the buildup and reservoir sections have been drilled within schedule with no major NPT event and saved at least one week of rig days.

Research on High Temperature Mechanical Properties of Casing in Complex Environment Deep Well

2011 ◽  
Vol 383-390 ◽  
pp. 3510-3515
Author(s):  
Jun Wang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Reduction Factor ◽  
Effect Of Temperature ◽  
Strength Reduction Factor ◽  
Deep Well ◽  
High Temperature Mechanical Properties ◽  
Deep Wells ◽  
Tubing String ◽  
Grade Steel

To analyze the effect of high temperature on material properties of steel casing Q125 and V140 in complex deep wells, some experiments of casing material have been done at the temperature of room temperature to 350°C, and based on the former results the material property model of high-grade steel casing under the effect of temperature was established. To facilitate the design of oilfield, uniform strength reduction factor at 150°C and 200°C was given, which was applied to casing string and tubing string design under high temperature. Taking an ultra-deep field as an example, the results show that casing mechanical properties decreases with the temperature increasing; in the design process of high temperature well, the temperature effect is needed to consider.

scholarly journals An Experimental Study on the Mechanical Properties of High-Temperature Granite under Natural Cooling and Water Cooling

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yanan Gao ◽  
Yunlong Wang ◽  
Taiping Lu ◽  
Liuzhou Li ◽  
Jinwen Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
High Temperature ◽  
Poisson’S Ratio ◽  
Heating Temperature ◽  
Axial Strain ◽  
Peak Stress ◽  
Poisson's Ratio ◽  
Water Cooling ◽  
Cooling Methods

With the further development of deep rock mechanics engineering, such as the exploitation and utilization of geothermal resources, the exploitation of deep mineral resources, and the safe disposal of nuclear waste, the study of mechanical properties of deep high-temperature rock is gaining the attention of the researchers. However, not only the high temperature but also the cooling condition/method that will be used in the construction such as drilling cooling will also greatly affect the mechanical properties of the rock. In this paper, the mechanical behaviour and the evolution of the mechanical properties of the high-temperature (600°C–1,000°C) granite under different cooling methods are studied. The following conclusions can be obtained: (1) The peak stress of the granite decreases with the heating temperature. Compared with natural cooling, water cooling has a more significant effect on strength degradation. (2) The increase of the heating temperature increases the maximum axial strain of the granite. The water cooling method more greatly induces the maximum axial strain of granite than the natural cooling. The maximum axial strain of the specimen under the water cooling reaches 117.3% of that under natural cooling (800°C). (3) The elastic modulus of the granite decreases with the heating temperature. Water cooling will have a stronger effect on the reduction of the elastic modulus than natural cooling. The maximum difference value (2.02 GPa) of the elastic modulus under the different cooling methods occurs at the temperature of 800°C. (4) Poisson’s ratio of the granite increases with heating temperature, and the cooling method does not have an evident effect on it. The relationship between Poisson’s ratio and the heating temperature under different cooling methods can be described using the linear model. (5) According to the influence of the temperature on the peak stress, the elastic modulus, and Poisson’s ratio, the heating temperature domain can be divided into the unapparent zone, the significant zone, and the mitigation zone. (6) The thermal stress due to the nonuniform temperature field and the different thermal expansion coefficients is incompatible. Such incompatibility stresses the essences of the degradation of the mechanical properties of the granite.

scholarly journals Influence of Temperature on Mechanical Properties of AMCs

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 783 ◽  
Author(s):  
E.S. Caballero ◽  
Fátima Ternero ◽  
Petr Urban ◽  
Francisco G. Cuevas ◽  
Jesús Cintas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Gas Flow ◽  
Room Temperature ◽  
Tensile Tests ◽  
Effect Of Temperature ◽  
Matrix Composites ◽  
Vacuum Sintering ◽  
Ammonia Gas ◽  
Aluminium Powder

This research focused on studying the effect of temperature on the mechanical properties of aluminium matrix composites (AMCs) obtained by a powder metallurgy route. Aluminium powder was milled at room temperature for 5 h and using different atmospheres in order to achieve different amounts of reinforcement. The atmospheres employed were vacuum, confined ammonia, and vacuum combined with a short-time (5 and 10 min) of ammonia gas flow. After mechanical alloying, powders were consolidated by cold uniaxial pressing (850 MPa) and vacuum sintering (650 °C, 1 h). Hardness and tensile tests, on consolidated samples, were carried out at room temperature. Subsequently, the effect of temperature on both properties were evaluated. On one hand, the UTS and hardness were measured, again at room temperature, but after having subjected the sintered samples to a prolonged annealing (400 °C, 100 h). On the other hand, the tensile and hardness behaviour were also studied, while the samples are at high temperature, in particular 250 °C for UTS, and in the range between 100 and 400 °C for hardness. Results show that the use of ammonia gas allows achieving mechanical properties, at room and high temperature, higher than those of the commercial alloys EN AW 2024 T4, and EN AW 7075 T6.

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