A note on the relationship between induced mechanical stress and thermal stress in recumbent pigs

1984 ◽  
Vol 38 (2) ◽  
pp. 309-311 ◽  
Author(s):  
J. M. Bruce ◽  
C. R. Boon

ABSTRACTThe hypothesis is proposed that pigs will induce a mechanical stress, by huddling and over-lying, that is related to the degree of thermal stress experienced. Measurements of the floor area covered by groups of 12 pigs have been used to validate the hypothesis.

2010 ◽  
Vol 168-170 ◽  
pp. 1957-1960
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Hong Yang Liu

The temperature field distribution and thermal stress distribution in concrete has been studied by finite elements method to establish the relationship between the thermal stress and the temperature in this paper. The results show that the maximum thermal gradient and the maximum thermal stress in the concrete appears on the direction of greater structural dimension, and the thermal stress value is positively correlated with thermal gradient or saying temperature difference and elastic modulus, and is negatively correlated with the water content and air content.


2004 ◽  
Vol 08 (01) ◽  
pp. 35-41
Author(s):  
Hirotaka Sano ◽  
Norikazu Yamada ◽  
Shingo Maeda

In the current study, using the arthrogram, we developed two-dimensional finite element (FE) models of the human hip joint. To clarify the relationship between the stress distribution and the degree of acetabular dysplasia, three FE models were established and analyzed. The models varied only in the degree of the bony covering of the femoral head; i.e. the center-edge (CE) angle=20, 10, 0 degrees. An edge load (x=0 N, y=600 N) was then applied on the distal border of the femur to simulate the bearing of the body weight. In the CE=20 degree model, no definite stress concentration was seen at the site of the labrum. On the other hand, the stress concentration was seen from the attachment of the labrum to the superior aspect of the acetabulum in the CE=0 degree model. The site of stress concentration clearly corresponded to the lesions where the acetabular rim pathologies were seen in the clinical practice. Moreover, we found that the Von Mises stress increases dramatically with decreasing the CE angle at the attachment of the labrum. In the dysplastic hip, the mechanical stress increases significantly at the supero-lateral aspect of the acetabulum, which eventually leads to the tearing or detachment of the labrum.


Author(s):  
Tatsuo Nishizawa ◽  
Shigeru Shimeno ◽  
Akinori Komatsubara ◽  
Masashi Koyanagawa

In the structural design of composite pavement with a concrete pavement slab overlaid with an asphalt surface course, it is very important to estimate the temperature gradient in the concrete slab. An asphalt surface course reduces the temperature gradient in an underlaid concrete slab, resulting in the reduction of thermal stress of the concrete slab. This effect was investigated by temperature measurement in model pavements and by thermal conductivity analysis. Thermal properties were estimated by a backanalysis by using measured temperatures over 1 year. From the numerical simulations varying the thickness of asphalt surface and concrete slab, the relationship between the reduction effect and the asphalt thickness was derived as a function of the thickness of asphalt surface course, which can be used in the structural design of the composite pavement.


Author(s):  
Gao Ao ◽  
Xia Gang ◽  
Kong Yong

In order to study the effect of mechanical-stress on the quartz filter output, based on the elasto-optical effect of quartz crystal, the relationship between berifringent difference of quratz plate and mechanical-stress is deduced, the experimental system is set up by using Ultra-6600 UV spectrophotometer, and received the transmission spectrum of Lyot quartz birefringence filter, the transmission spectrum was investigated theoretically and experimentally in detail. The results show that when applied different mechanical stresses, the center wavelength of quartz birefringent filter changed, and the drifting direction of the center wavelength is related to the size of applied mechanical stress, the drifting size of the center wavelength is related to the direction of applied mechanical stress. It is helpful for the manufacturing, correct design and application of quartz birefringence filter.


Kursor ◽  
2020 ◽  
Vol 10 (3) ◽  
Author(s):  
Yose Rizal ◽  
Imam Robandi ◽  
Eko Mulyanto Yuniarno

Natural lighting is an important factor that affects the comfort of building users. Natural lighting in a room requires a window area of ​​at least 1/6 of the floor area. This study was conducted to obtain the distribution of Daylight Factor (DF) as a natural lighting factor during the day in the room, based on the shift in the position of the window on the wall. The distribution of lighting entering the depth of the room through window openings is a tool to compare the best window position in the spread of illumination with DF calculations based on Sky Component (SC). Shifting the window position will be analyzed by Standard Deviation (S) and Mean (μ) based on the DF distribution. Optimizations of the DF distribution on the window position shifts if it has the largest DF mean value and the smallest DF variant value. The results of the study in a simple room showed that the optimal DF distribution was at the window position in the middle and the mean value was 2.59%. The relationship of shifting window position and DF distribution can be useful for architects to determine the function of a room in architectural design.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yasumori Sobue ◽  
Nobunori Takahashi ◽  
Yoshifumi Ohashi ◽  
Mochihito Suzuki ◽  
Tsuyoshi Nishiume ◽  
...  

Abstract CD44 fragmentation is enhanced in chondrocytes of osteoarthritis (OA) patients. We hypothesized that mechanical stress-induced enhancement of CD44-intracellular domain (CD44-ICD) production plays an important role in the de-differentiation of chondrocytes and OA. This study aimed to assess the relationship between CD44-ICD and chondrocyte gene expression. Monolayer cultured primary bovine articular chondrocytes (BACs) were subjected to cyclic tensile strain (CTS) loading. ADAM10 inhibitor (GI254023X) and γ-secretase inhibitor (DAPT) were used to inhibit CD44 cleavage. In overexpression experiments, BACs were electroporated with a plasmid encoding CD44-ICD. CTS loading increased the expression of ADAM10 and subsequent CD44 cleavage, while decreasing the expression of SOX9, aggrecan, and type 2 collagen (COL2). Overexpression of CD44-ICD also resulted in decreased expression of these chondrocyte genes. Both GI254023X and DAPT reduced the production of CD44-ICD upon CTS loading, and significantly rescued the reduction of SOX9 expression by CTS loading. Chemical inhibition of CD44-ICD production also rescued aggrecan and COL2 expression following CTS loading. Our findings suggest that CD44-ICD is closely associated with the de-differentiation of chondrocytes. Excessive mechanical stress loading promoted the de-differentiation of BACs by enhancing CD44 cleavage and CD44-ICD production. Suppression of CD44 cleavage has potential as a novel treatment strategy for OA.


2019 ◽  
Vol 2019 (HiTen) ◽  
pp. 000052-000055
Author(s):  
G.D. Liu ◽  
C.H. Wang

Abstract The silver nanoparticle paste is a promising material for high temperature die-attach applications. In this paper, the finite element method is used to study the relationship between the thickness of the sintered silver layer and the thermal stress in the sintered silver joint. Silicon chips are bonded together with sintered silver layers of different thicknesses. In the experimental study, strain gauges are attached onto the surface of the upper silicon and used to estimate the effects of the nano silver die-attach layer. The results show that the average stress in the silver layer at the interface decreases with the increasing thickness of the silver layer, while the stress on the silicon surface increases with the increasing thickness of the silver layer.


2013 ◽  
Vol 572 ◽  
pp. 359-362 ◽  
Author(s):  
Yu Mei Hu ◽  
Fang Jian Zhang ◽  
Yi Min Shao

Involute helical gears are widely used in high-speed and heavy-load transmission systems of automobiles, helicopters, etc. Poor working conditions lead to fatigue crack and other faults of gear key parts such as tooth face and tooth root. To identify the root causes of gear faults, strain monitoring methods are often used to monitor the stress changes of gear key parts so as to work out individualized improvement plans. However, stress of gears in the work process is typically the result of the coupling effect of thermal stress and mechanical stress. The existing strain monitoring methods cannot separate them effectively, and thus it is impractical to quickly find the corresponding improvement measures. To reveal the coupling relationship between thermal stress and mechanical stress during gear meshing and find out the source of gear faults, this paper uses the transient finite element-based analysis method to study the coupling relationship between thermal strain and mechanical strain of a pair of helical gears in the test direction and find the coupling rules of thermal strain and mechanical strain among the strains of gears in the strain test direction that may provide effective guidance for the fault diagnosis of gear meshing.


2014 ◽  
Vol 535 ◽  
pp. 460-463
Author(s):  
Dong Yin Han

The techniques are referred to as analyzing the relationship between the events of the lithosphere getting thermal and the changes of weakened release energies of strong earthquakes that might be related with the ones of increased exploitation quantities of the global three-large fossil fuels of coal,oil and gas ,and the relationship between the events of earth crust expansion getting thermal with the accumulated increasing of the land crust expansion thickness from calculation and the accumulated increasing of fossil fuels being exploited,et al. The three mechanism-modes of earth's epidermis warming over the past 100 years since 1890 from earth interior changes with relation to fossil fuels being exploited were suggested that the weakened release energies of global strong earthquakes caused by the increasing of earth thermal stress energies and overall warming of lithosphere, the “weightlessness” and expansion and getting thermal of continental crust,the increasing of earth currents and heat quantities generated by added origid geological and tectonic activities in mining areas and earth's surface getting thermal.


2014 ◽  
Vol 63 (4) ◽  
pp. 579-590
Author(s):  
D. Bellan

Abstract Modern electrical-power systems are often exploited for transmitting high-frequency carrier signals for communications purposes. Series-connected air-core coils represent the fundamental component allowing such applications by providing a proper filtering in the frequency domain. They must be designed, however, to withstand also the line short-circuit current. When a high-magnitude current flows through a coil, strong mechanical stresses are produced within the conductor, leading to possible damage of the coil. In this paper, an approximate analytical model is derived for the relationship between the maximum mechanical stress and the electrical/geometrical parameters of the coil. Such a model provides the guidelines for a fast and safe coil design, whereas numerical simulations are only needed for the design refinement. The presented approach can be extended to other applications such as, for example, the mechanical stress resulting from the inrush currents in the coils of power transformers.


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