Combined Effect of Temperature and Soil Load on Buried HDPE Pipe

HDPE pipes，mostly buried underground, have been widely used in industry. Much research has been done on pipe property changing with time or temperature. But thermal expansion of pipe was neglected. This paper investigated the combined effect of soil load and temperature on HDPE pipe with introduction of thermal expansion. Stress and deflection variation with time of buried HDPE pipe were studied in ABAQUS. Result showed pipe temperature had great influence on buried HDPE pipe performance. Thermal stress was much larger than stress caused by soil load. And thermal expansion prevented pipe from deflecting due to soil load, which can protect HDPE pipe in applications.

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Combined Effect of Temperature and Soil Load on Buried HDPE Pipe

Advanced Materials Research ◽

10.4028/scientific5/amr.452-453.1169 ◽

2012 ◽

Vol 452-453 ◽

pp. 1169-1173

Author(s):

Zheng Li ◽

Hong Wu Zhu ◽

Xiang Ling Kong ◽

Abdennour Seibi

Keyword(s):

Combined Effect ◽

Effect Of Temperature ◽

Hdpe Pipe ◽

Soil Load

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Out-of-Plane Thermal Expansion Coefficient and Biaxial Young’s Modulus of Sputtered ITO Thin Films

Coatings ◽

10.3390/coatings11020153 ◽

2021 ◽

Vol 11 (2) ◽

pp. 153

Author(s):

Chuen-Lin Tien ◽

Tsai-Wei Lin

Keyword(s):

Thin Films ◽

Thermal Expansion ◽

Thermal Stress ◽

Young’S Modulus ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Young's Modulus ◽

Heating Temperature ◽

Glass Substrates ◽

Ito Thin Films

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.

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Negative thermal expansion in YbMn2Ge2 induced by the dual effect of magnetism and valence transition

npj Quantum Materials ◽

10.1038/s41535-021-00348-z ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Yongqiang Qiao ◽

Yuzhu Song ◽

Andrea Sanson ◽

Longlong Fan ◽

Qiang Sun ◽

...

Keyword(s):

Thermal Expansion ◽

Intermetallic Compound ◽

Cell Volume ◽

Valence State ◽

Unit Cell Volume ◽

Negative Thermal Expansion ◽

Combined Effect ◽

Dual Effect ◽

Valence Transition ◽

Magnetovolume Effect

AbstractNegative thermal expansion (NTE) is an intriguing property, which is generally triggered by a single NTE mechanism. In this work, an enhanced NTE (αv = −32.9 × 10−6 K−1, ΔT = 175 K) is achieved in YbMn2Ge2 intermetallic compound to be caused by a dual effect of magnetism and valence transition. In YbMn2Ge2, the Mn sublattice that forms the antiferromagnetic structure induces the magnetovolume effect, which contributes to the NTE below the Néel temperature (525 K). Concomitantly, the valence state of Yb increases from 2.40 to 2.82 in the temperature range of 300–700 K, which simultaneously causes the contraction of the unit cell volume due to smaller volume of Yb3+ than that of Yb2+. As a result, such combined effect gives rise to an enhanced NTE. The present study not only sheds light on the peculiar NTE mechanism of YbMn2Ge2, but also indicates the dual effect as a possible promising method to produce enhanced NTE materials.

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Unravelling thermal stress due to thermal expansion mismatch in metal–organic frameworks for methane storage

Journal of Materials Chemistry A ◽

10.1039/d0ta09462e ◽

2021 ◽

Author(s):

Jelle Wieme ◽

Veronique Van Speybroeck

Keyword(s):

Thermal Expansion ◽

Thermal Stress ◽

Pressure Coefficient ◽

Metal Organic Frameworks ◽

Methane Storage ◽

Thermal Expansion Mismatch ◽

Thermal Pressure ◽

Temperature Changes ◽

Metal Organic ◽

The Impact

Thermal stress is present in metal–organic frameworks undergoing temperature changes during adsorption and desorption. We computed the thermal pressure coefficient as a proxy for this phenomenon and discuss the impact of thermal expansion mismatch.

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