Determination of Thermal Stresses in Three-Ply Laminates

1955 ◽  
Vol 22 (2) ◽  
pp. 190-192
Author(s):  
A. J. Durelli ◽  
C. H. Tsao

Abstract The knowledge of the distribution of stresses produced in three-ply laminates when the temperature changes is very important in the design of airplane windshields. This paper gives the result of a photoelastic investigation on the thermal stresses produced in a three-ply laminate consisting of glass, polyvinyl butyral, glass, when the temperature drops slowly from 70 to −20 F. The maximum stress has been found to be about six and one-half times the average longitudinal stress at the mid-section of the glass. Failure characteristics of the laminates check well with these findings. No new methods have been developed in the paper; however, the presently available techniques had to be applied carefully to determine maximum tensile stresses of about 1300 psi on the interface, at a distance of about 0.007 in. from the edge, at low temperature.

1991 ◽  
Vol 113 (4) ◽  
pp. 425-427 ◽  
Author(s):  
A. O. Cifuentes

This technical note shows that the determination of the stresses induced in multi-metal beams by temperature changes reduces to solving a linear system of equations. This system of equations has a very particular structure that allows one to obtain a closed form solution easily.


2018 ◽  
Vol 935 ◽  
pp. 121-126
Author(s):  
Stepan V. Litvinov ◽  
L.I. Trush ◽  
Serdar B. Yazyev

The determination of the stress-strain state of a polymer body has many difficulties. This is due to the fact that the properties of polymers vary greatly from various perturbations, and are especially strongly dependent on temperature changes. Currently, rotating structures and their elements are increasingly made of polymer materials. Particularly it is possible to single out the problem if a change in temperature is observed along the radius, which leads to a change in the properties of the material. This circumstance can radically change the picture of the distribution of stresses and deformations in the thickness of the structure under study. Neglect of this fact can adversely affect the reliability of the structure as a whole.


1997 ◽  
Vol 36 (11) ◽  
pp. 101-106 ◽  
Author(s):  
January Bien ◽  
Lidia Wolny

Studies of sewage sludge conditioning by ultrasonic field concentrate on determination of the increase of water removal effect, which depends on kind of sludge and chemical compounds used in the dewatering process. An attempt was made to find new methods of sludge preparation before dewatering. Tests presented here focused on digested and difficult dewatered sludge. The sludge was dewatered on a vacuum filter after conditioning with polyelectrolytes and the ultrasonic field. The microscopic analysis was an additional criterion to evaluate changes in the sludge structure after preparation. The polyelectrolyte dose of 3 mg/g d.m. sonicated within 15 sec. resulted in the 50% decrease of sludge volume. Results presented confirmed our previous experiences, concerning the relation between conglomerates of sludge and the effect of dewatering.


1980 ◽  
Vol 45 (8) ◽  
pp. 2315-2318 ◽  
Author(s):  
Vladimír Pollák ◽  
Andrej Romanov

The relative charge of the internal energy, fU/f, during deformation of cross-linked elastomers, poly(ethylene-co-propylene) and poly(ethylene-co-vinyl acetate), was determined at various temperatures. Anomalies in the dependence of fU/f on relative dilatation in the region of small deformations ( 35%) are to a large extent besides other factors due to the sensibility of the formula used to calculate fU/f to temperature changes.


1974 ◽  
Vol 41 (3) ◽  
pp. 647-651 ◽  
Author(s):  
Myron Levitsky ◽  
Bernard W. Shaffer

A method has been formulated for the determination of thermal stresses in materials which harden in the presence of an exothermic chemical reaction. Hardening is described by the transformation of the material from an inviscid liquid-like state into an elastic solid, where intermediate states consist of a mixture of the two, in a ratio which is determined by the degree of chemical reaction. The method is illustrated in terms of an infinite slab cast between two rigid mold surfaces. It is found that the stress component normal to the slab surfaces vanishes in the residual state, so that removal of the slab from the mold leaves the remaining residual stress unchanged. On the other hand, the residual stress component parallel to the slab surfaces does not vanish. Its distribution is described as a function of the parameters of the hardening process.


2021 ◽  
Author(s):  
Eryn Nelson ◽  
Jeffrey S. S. K. Formen ◽  
Christian Wolf

The widespread occurrence and significance of chiral compounds does not only require new methods for their enantioselective synthesis but also efficient tools that allow rapid determination of the absolute configuration,...


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3509
Author(s):  
Paule Marcoux-Valiquette ◽  
Cécile Darviot ◽  
Lu Wang ◽  
Andrée-Anne Grosset ◽  
Morteza Hasanzadeh Kafshgari ◽  
...  

Reliable cytopathological diagnosis requires new methods and approaches for the rapid and accurate determination of all cell types. This is especially important when the number of cells is limited, such as in the cytological samples of fine-needle biopsy. Immunoplasmonic-multiplexed- labeling may be one of the emerging solutions to such problems. However, to be accepted and used by the practicing pathologists, new methods must be compatible and complementary with existing cytopathology approaches where counterstaining is central to the correct interpretation of immunolabeling. In addition, the optical detection and imaging setup for immunoplasmonic-multiplexed-labeling must be implemented on the same cytopathological microscope, not interfere with standard H&E imaging, and operate as a second easy-to-use imaging method. In this article, we present multiplex imaging of four types of nanoplasmonic markers on two types of H&E-stained cytological specimens (formalin-fixed paraffin embedded and non-embedded adherent cancer cells) using a specially designed adapter for SI dark-field microscopy. The obtained results confirm the effectiveness of the proposed optical method for quantitative and multiplex identification of various plasmonic NPs, and the possibility of using immunoplasmonic-multiplexed-labeling for cytopathological diagnostics.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2889
Author(s):  
Jacek Kukulski ◽  
Piotr Gołębiowski ◽  
Jacek Makowski ◽  
Ilona Jacyna-Gołda ◽  
Jolanta Żak

The correct operation of the continuous welded track requires diagnosing its condition and preparation of track metrics requiring measurements of displacements of rail under operation. This is required as there are additional thermal stresses in the rails with values depending on the temperature changes of the rails. Therefore, the climatic conditions are important. This paper presents the original effective analytical method for diagnosing the condition of continuous welded track based on experimental research. The method allows for an appropriate repair or maintenance recommendation. In the experimental research, the authors considered track diagnostic conditions for two conditions: track under load and track without load. This paper presents empirical formulas for calculating rail temperature and longitudinal force based on ambient temperature, developed from long-term measurements. The formulas were developed for a track located on a straight section—both for a rail loaded and unloaded with a passing train under the following conditions: 60E1 rail, not on an engineering structure, conventional surface, wooden sleepers and very high train traffic load. The obtained results in the value of the correlation coefficient R2 ≥ 0.995 attest to very high accuracy of the calculations performed with the method proposed by the authors.


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