THE ANALYSIS OF STRESS DEFORMATION STATE PECULIARITIES OF MASONRY UNITS AND BED JOINTS

2011 ◽  
Vol 3 (3) ◽  
pp. 105-111 ◽  
Author(s):  
Robertas Zavalis ◽  
Bronius Jonaitis
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Contact Zone ◽  
Strain Analysis ◽  
Stress Strain ◽  
Curing Conditions ◽  
Stiffness Properties ◽  
Deformation State ◽  
Masonry Units

In this paper, the analysis of various effects that have influence to the mechanical properties of masonry is made. Masonry is nonhomogeneous and anisotropic material composed of two materials with different stiffness properties. In order to analyze masonry deformations it is necessary to evaluate all effects that have influence to masonry mechanical properties (Table 1). The analysis of stress-strain state of masonry is presented in this paper. During the analysis of stressstrain state, the mechanical properties of masonry units and mortar were defined from experimental investigation of samples of unit and mortar materials. The following conclusions were reached based on the analysis of experimental data: 1) The deformations and stresses along the height of masonry unit distributes unevenly. The stresses and deformations near the bed joint are higher than in the middle of the unit (4 pav). 2) From experimental data it was determined that the deformation of bed joints mostly depend on contact zone between units and mortar. The contact zone deformation contains about 80…90% of all bed joint deformation. 3) The elastic modulus of mortar inside the composite is different from modulus of mortar specimens cast separately due to different laying and curing conditions. The elastic modulus values performed from composite were 15…25 times less than the values from standard mortar prisms (EN 1015-11). It is advisable to use real (defined from experiments) masonry units and mortar properties when detailed, numerical stress-strain analysis is performed. 4) Experimental analysis showed that bed joints have big influence to vertical deformation of masonry in axial compression. Masonry units have influence to mechanical properties of mortar joints. The experiment was carried out, during which dry and wet masonry units were used. Units were wet out to eliminate there absorption characteristics. Extra wet out units had an effect to the stiffness of bed joints (12 pav).

Effect of Porosity on Mechanical Properties of Rubber

1995 ◽  
Vol 68 (2) ◽  
pp. 219-229 ◽  
Author(s):  
A. I. Kasner ◽  
E. A. Meinecke
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Shape Factor ◽  
Compression Modulus ◽  
Stress Strain ◽  
Shape Factors ◽  
Porosity Level ◽  
Apparent Modulus ◽  
Analytical Expressions ◽  
Cylindrical Samples

Abstract Cylindrical samples, with different shape factors and levels of porosity, were prepared from a model EPDM compound and tested in compression. The modulus was reduced considerably with the introduction of porosity, especially when the shape factor was high. The stress-strain curves showed nonlinearity which depends on the shape factor and porosity level, and is related to bubble closure. The apparent modulus of bonded blocks was found to consist of two components: homogeneous compression modulus and a hydrostatic contribution. The first was obtained by compression of blocks between lubricated compression plates. It can be predicted from analytical expressions adapted from composite theories for high density foams in tension. The second arises from the pressure buildup inside the bonded blocks and depends on the shape factor and the porosity level. These moduli, after correcting for compressibility, were used to develop approximate relations describing the stress-strain curves of porous bonded blocks. The stress-strain curves of samples with different shape factors and levels of porosity could be predicted from experimental data or FEA estimates.

Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 178-181
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Ling Chao Kong ◽  
Wei Du
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Variable Temperature ◽  
Improve Performance ◽  
Curing Conditions ◽  
Fly Ash Concrete ◽  
Better Than

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.

scholarly journals MECHANICAL PROPERTIES OF SANDSTONE SUBJECTED TO COUPLING OF TEMPERATURE–SEEPAGE–STRESS

10.6036/10055 ◽  
2021 ◽  
Vol 96 (3) ◽  
pp. 309-315
Author(s):  
Lijie Long ◽  
Dongyan Liu ◽  
Dong Wang ◽  
Jin Li
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Rock Mass ◽  
Elastic Modulus ◽  
Plastic Zone ◽  
Residual Strength ◽  
Confining Pressure ◽  
Peak Strength ◽  
Hydraulic Pressure ◽  
Stress Strain

ABSTRACT: The deformation and fracture of rock mass in deep rock mass engineering are affected by the coupling of temperature, seepage, and stress. A test and a calculation model for sandstone under thermal–hydrological–mechanical (THM) coupling were proposed to reveal the mechanical properties of sandstone. The law of coupling for mechanical indicators of sandstone was established by laboratory tests and numerical simulations. The permeability, peak strength, peak strain, residual strength, elastic modulus, plastic deformation area, and stress–strain cloud diagram were analyzed by the steady state seepage method and THM coupling principle, and the accuracy of the model was verified. Results demonstrate that: (1) As the temperature rises and the peak deformation increases, the sample slowly drops to the residual strength level after the peak stress. (2) The main factor that affects peak strength is confining pressure. In the temperature range of 25 °C–50 °C, the maximum peak strength and peak deformation are increased by heating, and the increases in confining pressure and temperature reduce the reduction coefficient of the residual strength. Moreover, the elastic modulus increases with the increase in confining pressure, but it shows a downward trend when the temperature increases. (3) The plastic deformation zone and stress–strain cloud diagram indicated that when the temperature and osmotic pressure increase, the specimen enters the plastic zone earlier, the effective plastic zone increases, the stress increases, and the deformation is intensified. The proposed method provides a certain reference for the permeability and stability evaluation of rock mass under the conditions of “three-high” (high confining pressure, high hydraulic pressure, and high stress) engineering. Keywords: temperature–seepage–stress coupling, sandstone, mechanical properties

Effects of Ice Content on Mechanical Behavior of Frozen Loess under Uniaxial Compression

2014 ◽  
Vol 919-921 ◽  
pp. 666-669
Author(s):  
Xiang Tian Xu ◽  
Cai Xia Fan ◽  
Jun Hong Yuan
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Loading Rate ◽  
Failure Strain ◽  
Stress Strain ◽  
Ice Content ◽  
Strain Increase ◽  
Compressive Tests

The uniaxial compressive tests on frozen loess with different ice content under loading rate of 1.25mm/min at-6°C are carried out to investigate the effects of ice content on the mechanical behavior of ice. The influence of ice content on stress-strain, elastic modulus, strength and failure strain of frozen loess are analyzed based on the experimental data. The results show that strength and failure strain increase with increasing of ice content. The elastic modulus first increase and then decrease with increasing of ice content.

Determining Stress-Strain Behavior of Zr60Cu10Al15Ni15 Bulk Metallic Glass Using Object Oriented Finite Element Analysis

2017 ◽  
Vol 29 ◽  
pp. 1-8 ◽  
Author(s):  
Ketul Arvindbhai Patel ◽  
Ganesh R. Karthikeyan ◽  
S. Vincent
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Metallic Glass ◽  
Strain Analysis ◽  
Indentation Test ◽  
Object Oriented ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior

Determining mechanical properties of Bulk Metallic Glasses (BMGs) requires synthesizing of the alloys in bulk form. However obtaining metallic glass in bulk form is quite challenging due to its tendency towards crystallization. In such circumstances it is beneficial to determine the mechanical properties of materials using finite elemental analysis of microstructures. Thus, in the present investigation, using Object Oriented Finite Element Analysis (OOF2) software package, Stress-Strain analysis has been carried out on Zr60Cu10Al15Ni15 BMG to determine such mechanical properties. Specimen of Zr60Cu10Al15Ni15 BMG exhibiting three microstructurally distinct regions amorphous, partial crystalline and crystalline regions was used for this analysis. The Stress-Strain relationship have been estimated for each of the three distinct phases and the results are validated by determining the Modulus of Elasticity for all the phases and comparing it with the available experimental results from Nano-indentation test.

The Research of Test on Stress-Strain Constitutive Relations of Straw Concrete

2014 ◽  
Vol 584-586 ◽  
pp. 987-992
Author(s):  
Wei Liu ◽  
Wei Xi ◽  
Yi Lu Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Constitutive Relations ◽  
Strain Curve ◽  
Green Building ◽  
Corn Straw ◽  
Stress Strain Curve ◽  
Stress Strain

As a new green building material, straw concrete are introduced about its mechanical properties and characteristics. Mechanical properties test such as prism compressive strength, elastic modulus and Poisson's ratios use standard prismatic blocks. Under different rate of corn straw, cement, sand and fly ash, test gets the full stress-strain curve. Results show that with increase of volume of corn straw, the prism compressive strength reduces significantly. Comparing with natural concrete, elastic modulus of straw concrete can reduces greatly. Poisson’s ratio reduces with increase of volume of corn straw. Fly ash could improve property of the material and replace cement, but excessive replacement will reduce the strength of material.

Effect of osmolarity on the zero-stress state and mechanical properties of aorta

2007 ◽  
Vol 293 (4) ◽  
pp. H2328-H2334 ◽  
Author(s):  
Xiaomei Guo ◽  
Yoram Lanir ◽  
Ghassan S. Kassab
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Stress State ◽  
Water Content ◽  
Wall Thickness ◽  
Circumferential Stress ◽  
Opening Angle ◽  
Stress Strain ◽  
Wall Area ◽  
Induced Changes

Some pathological conditions may affect osmolarity, which can impact cell, tissue, and organ volume. The hypothesis of this study is that changes in osmolarity affect the zero-stress state and mechanical properties of the aorta. To test this hypothesis, a segment of mouse abdominal aorta was cannulated in vivo and mechanically distended by perfusion of physiological salt (NaCl) solutions with graded osmolarities from 145 to 562 mosM. The mechanical (circumferential stress, strain, and elastic modulus) and morphological (wall thickness and wall area) parameters in the loaded state were determined. To determine the osmolarity-induced changes of zero-stress state, the opening angle was observed by immersion of the sectors of mouse, rat, and pig thoracic aorta in NaCl solution with different osmolarities. Wall volume and tissue water content of the rings were also recorded at different osmolarities. Our results show that acute aortic swelling due to low osmolarity leads to an increase in wall thickness and area, a change in the stress-strain relationship, and an increase in the elastic modulus (stiffness) in mouse aorta. The opening angle, wall volume, and water content decreased significantly with increase in osmolarity. These findings suggest that acute aortic swelling and shrinking result in immediate mechanical changes in the aorta. Osmotic pressure-induced changes in the zero-stress state may serve to regulate mechanical homeostasis.

scholarly journals Study on mechanical properties of granite minerals based on nanoindentation test technology

2021 ◽  
Vol 25 (6 Part B) ◽  
pp. 4457-4463
Author(s):  
Man Lei ◽  
Fa-Ning Dang ◽  
Hai-Bin Xue ◽  
Zhang Yu ◽  
Ming-Ming He
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Mineral Composition ◽  
Energy Analysis ◽  
Nanoindentation Test ◽  
Displacement Curve ◽  
Analysis Method ◽  
Test Technology

In this paper, the nanoscale mechanical properties of quartz, feldspar, and mica in granite are studied by the nanoindentation technique. Firstly, the surface morphol?ogy of each mineral composition in granite is obtained by a SEM. Secondly, the elastic modulus and hardness of three minerals in granite are calculated through the load-displacement curve obtained by the nanoindentation test. Based on the energy analysis method, the nanometer fracture toughness of three minerals in granite is obtained. Finally, the correlation between the elastic modulus, the hard?ness, and the fracture toughness are obtained by experimental data.

scholarly journals About One of the Approaches for the Research of the Stress-Strain State of a Flange Connection with a Seal Made of an Alloy with Shape Memory

2022 ◽  
Author(s):  
A. Boikov
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Contact Zone ◽  
Axial Compression ◽  
Strain State ◽  
Physical And Mechanical Properties ◽  
Stress Strain ◽  
Flange Connection ◽  
Stress Strain State ◽  
Alternative Approach

Abstract. Design features of a flange connection with a seal made of an alloy with shape memory and the most commonly used methods of researching of the stress-strain state of such connections are estimated. Alternative approach for stress-strain state analysis is proposed, it is based on modeling of the contact zone of the sealing surfaces by means of an equivalent gap between the layers, the value of which changes during axial compression of the multilayer ring and goes into tension. Formulas for determining of contact stresses at the border of layers, which take into consideration the variable physical and mechanical properties of the materials of each layer are presented.

scholarly journals An Experimental Investigation of the Stress-Strain Behaviour of Geopolymer Concrete

2018 ◽  
Vol 26 (2) ◽  
pp. 30-34 ◽  
Author(s):  
M. Venu ◽  
T. D. Gunneswara Rao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Stress Strain ◽  
Curing Conditions ◽  
Strain Behaviour ◽  
Measured Stress

AbstractThis paper focuses on the mechanical properties and modulus of elasticity of fly ash and GGBS based geopolymer concrete. In this study an 8 molarity concentration of NaOH and alkaline liquid ratio in a ratio of 2.5 was used. This study includes the stress-strain behaviour along with the flexural strength, compressive strength and split tensile strengths for the GPC20, GPC40 and GPC60 grades. Tests were carried out on 150 mm × 150 mm × 150 mm cubes and 100 × 100 × 500 mm prisms and 150 × 300 mm cylindrical geopolymer concrete specimens. The test results not- ed the good mechanical properties and measured stress-strain relations of fly ash and GGBS based geopolymer concrete under ambient curing conditions. The elastic modulus was significantly varied with increases in the grade of the concrete. An equation was proposed to determine the modulus of elasticity based on the compressive strength of the geopolymer concrete.

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