Evaluation of the coefficients of mutual influence of wood through off-axis compression tests

2012 ◽  
Vol 30 ◽  
pp. 522-528 ◽  
Author(s):  
Nilson Tadeu Mascia ◽  
Leandro Vanalli
2004 ◽  
Vol 467-470 ◽  
pp. 429-434 ◽  
Author(s):  
Petra Backx ◽  
Matthew R. Barnett ◽  
Leo Kestens

The mechanical anisotropy of wrought Mg alloys is very high. For example the yield stress of extruded Mg-3Al-1Zn tested in tension can be as high as twice that obtained in compression [1]. To solve the problems this creates for product design it is necessary to understand the sensitivity of texture to processing parameters. Uniaxial compression tests at different temperatures were performed on cylindrical samples of an extruded Mg-3Al-1Zn bar. The texture during this deformation changes from a situation where all crystal c-axes are nearly perpendicular to the sample axis to one where the c-axes are all nearly parallel to this axis. Compression was stopped at different strains to examine the rate of this texture change. Textures were examined using EBSD measurements. It was found that different mechanisms operate depending on the temperature of deformation and that a variety of textures can be created. Also it was seen that an annealing treatment performed after compression has an influence on the texture. Afterwards the samples were subjected to another uniaxial compression test to examine the influence of texture on room temperature properties.


Holzforschung ◽  
2019 ◽  
Vol 73 (3) ◽  
pp. 251-258
Author(s):  
Hiroshi Yoshihara

Abstract Off-axis compression tests (OACT) were conducted on solid wood from six tree species, and the relationship between the off-axis compressive strength (OACStr) and the off-axis angle was predicted under the conventional Hill-type quadratic failure conditions, off-axis special failure conditions, and under a condition proposed in this study, which contains terms of interaction between the normal and shear stresses. The latter was an effective approach for accurately predicting the OACStr, although the physical meaning of the interaction terms is not yet clear. Under the off-axis specialized conditions, the approach was simple and accurate for predicting the OACStr, which includes the 45° off-axis angle.


2020 ◽  
Vol 51 (11) ◽  
pp. 5790-5805
Author(s):  
Marek Wojtaszek ◽  
Grzegorz Korpała ◽  
Tomasz Śleboda ◽  
Krystian Zyguła ◽  
Ulrich Prahl

Abstract The influence of the total deformation amount on the microstructure and selected properties of Ti-6Al-4V alloy was determined in this study. Multi-axis compression tests on the MaxStrain module were performed to obtain large strains. Starting material for the research was obtained by the powder metallurgy (PM) route. Plastically processed cast alloy of the same chemical composition as PM alloy was also tested as reference material. The tests were performed with the cooling of samples between successive deformation stages, which allowed for the simulation of the temperature drop occurring during industrial processes. The multi-stage deformation ability of PM Ti-6Al-4V alloy without decohesion was confirmed. It has also been shown that the application of increasing total strain at a controlled temperature changes the samples resulting in the refinement of the microstructure and leads to the fragmentation of lamellae. The results obtained from MaxStrain tests were verified by multi-stage hot-rolling tests. Defect-free products were obtained, whose good quality was confirmed by the microstructural observations as well as by the investigations of their properties. The results of the rolling tests confirmed the possibility of hot processing of Ti-6Al-4V alloy compacts in industrial conditions, applying large total strain.


Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.


Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).


2019 ◽  
Vol 66 (5) ◽  
pp. 640-649 ◽  
Author(s):  
Gianluca Lo Coco ◽  
Salvatore Gullo ◽  
Gabriele Profita ◽  
Chiara Pazzagli ◽  
Claudia Mazzeschi ◽  
...  

Author(s):  
Ye.Ye. Nikitin

The current situation in the sphere of district heating is analysed on the basis of use of the cognitive approach. The presence of closed chains of cause-effect relationships of negative factors and conflicts of target settings of the subjects in the field of district heating is shown. The conceptual model of energy efficient modernization of district heating systems is proposed. This model includes indicators of the current status of heat sources, networks and heat consumers, energetic and economic models, restrictions, procedure of forming and analysis of the mutual influence of the recommended projects. The quantitative data on indicators of the current state of district heating systems of the cities of Ukraine are presented. The interrelation between indicators of the current state and projects of energy efficient modernization of district heating systems is shown. Assessment of energy self-sufficiency of municipal district heating systems on condition of thermal modernization of buildings is carried out. The creation of energy management systems at the district heating enterprises is proposed. Bib. 6, Fig. 7, Tab. 5.


2020 ◽  
Vol 3 (1) ◽  
pp. 50-59
Author(s):  
Xu Jianqin

This article analyses the evolution of the mother–daughter relationship in China, and describes the mothering characteristics of four generations of women, which in sequence includes “foot-binding mothers”, “mothers after liberation”, “mothers after reform and opening up”, and “mothers who were only daughters”. Referring to Klein’s ideas about the mother–child relationship, especially those in her paper “Some reflections on ‘The Oresteia’ ”, the author tries to understand mothers and their impact on their daughters in these various periods of Chinese history, so as to explore the mutual influence of the mother–daughter relationship in particular, and the Chinese cultural and developmental context in general.


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