Micro-Strength Analysis of Sand Mold for Casting Based on Bonded-Particle Model

2016 ◽  
Vol 723 ◽  
pp. 316-321
Author(s):  
Fu Xian Zhu ◽  
Zhong De Shan ◽  
Fen Liu
Keyword(s):  
Tensile Strength ◽  
Mass Fraction ◽  
Experimental Results ◽  
Sand Mold ◽  
Strength Analysis ◽  
Particle Model ◽  
Beam Model ◽  
Bonded Particle Model ◽  
Strength Formula ◽  
The Relationship

The micro-strength of sand mold is analyzed based on bonded-particle model (BPM) due to the reason that the strength of sand mold largely influences the final casting properties. In this study, the stress and the strength as well as the stiffness parameters of the binding bridge between the sands are obtained firstly by establishing the equivalent micro-beam model of the binding bridge between the sands. Then, the tensile strength formula of Sand Mold is derived according to the idea packing shape of particle, which is then used for discussing the relationship between the tensile strength with the sand mesh and the mass fraction of binder. At last, the effects of the sand mesh and mass fraction of binder on the tensile strength of the Sand Mold are analyzed quantitatively, which shows the great agreement with the macroscopic experimental results of the sand mold strength.

scholarly journals Breakage Strength of Wood Sawdust Pellets: Measurements and Modelling

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3273
Author(s):  
Józef Horabik ◽  
Maciej Bańda ◽  
Grzegorz Józefaciuk ◽  
Agnieszka Adamczuk ◽  
Cezary Polakowski ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compression Test ◽  
Particle Model ◽  
Wood Pellets ◽  
Diametral Compression ◽  
Bonded Particle Model ◽  
Particle Bonding ◽  
Diametral Compression Test ◽  
Deformation Relationship ◽  
Insight Into

Wood pellets are an important source of renewable energy. Their mechanical strength is a crucial property. In this study, the tensile strength of pellets made from oak, pine, and birch sawdust with moisture contents of 8% and 20% compacted at 60 and 120 MPa was determined in a diametral compression test. The highest tensile strength was noted for oak and the lowest for birch pellets. For all materials, the tensile strength was the highest for a moisture content of 8% and 120 MPa. All pellets exhibited a ductile breakage mode characterised by a smooth and round stress–deformation relationship without any sudden drops. Discrete element method (DEM) simulations were performed to check for the possibility of numerical reproduction of pelletisation of the sawdust and then of the pellet deformation in the diametral compression test. The pellet breakage process was successfully simulated using the DEM implemented with the bonded particle model. The simulations reproduced the results of laboratory testing well and provided deeper insight into particle–particle bonding mechanisms. Cracks were initiated close to the centre of the pellet and, as the deformation progressed, they further developed in the direction of loading.

scholarly journals Estimation of the perpendicular-to-the-grain tensile strength of Scots pine glued laminated timber via three-point bending tests

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shigefumi Okamoto ◽  
Nobuhiko Akiyama ◽  
Noboru Nakamura ◽  
Kenji Aoki ◽  
Masahiro Inayama
Keyword(s):  
Tensile Strength ◽  
Size Effect ◽  
Scots Pine ◽  
Bending Strength ◽  
Experimental Results ◽  
Bending Tests ◽  
Three Point Bending ◽  
Specimen Height ◽  
Glued Laminated Timber ◽  
The Relationship

AbstractThree-point bending tests were performed on specimens of glued laminated timber with different specimen heights to failure to determine the relationship between specimen height and bending strength under tension perpendicular to the grain. For the three-point bending tests, two types of glued laminated timber composed of homogeneous grade timber, as specified in the Japanese Agricultural Standard, were used. The laminae used for the glued laminated timber were L80 grade Scots pine and L110 grade Scots pine. The specimens used in the three-point bending tests had dimensions of 105 mm (width) and 10–300 mm (height). The experimental results showed that the bending strength decreased as the specimen height increased, but the rate of decrease in the bending strength decreased with increasing specimen height when the specimen height exceeded 100 mm. From the relationship between the bending strength and specimen height, parameters that fit Bažant’s size-effect law were derived, and for a specimen height of approximately 100 mm, the bending strength was equal to the perpendicular-to-the-grain tensile strength.

Estimation of Tensile Strength of High Strength Concrete Based on Experimental Results

2019 ◽  
Vol 292 ◽  
pp. 56-62
Author(s):  
Radmila Sinđić Grebović ◽  
Marko Grebović
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Experimental Research ◽  
High Strength Concrete ◽  
High Strength ◽  
Experimental Results ◽  
Strength Analysis ◽  
Shear Stresses ◽  
Strength Concrete ◽  
Normal Strength

Use of high strength concrete require reliable predictions of correlations of compressive strength with tensile strength or splitting strength. Analysis of correlation between tensile strength of concrete and compressive strength, based on experimental results, is shown in this paper. It is proposed new simple correlation. Regression analysis that use, is based on the results of the experimental researches of compressive strength and splitting tensile strength, at specimens of high strength concrete. Comparative analysis of test results, gained for high strength concrete and normal strength concrete is performed. Analysis comprises the results of the experimental research of deep beams subjected to shear. Stresses measured on surfaces of high strength concrete beams subjected to shear and level of stresses that induce inclined cracks in concrete are applied. Relationship between concrete compressive strength and shear cracking stresses is studied, too. Experimental research was done at pairs of the beams made of concrete with high compressive strength and normal compressive strength. Estimation of validation of relations prescribed by the design codes for high strength concrete has performed.

Parasites and promiscuity: Acute disease salience leads to more restricted sexual attitudes

2021 ◽  
pp. 026540752110309
Author(s):  
James B. Moran ◽  
Nicholas Kerry ◽  
Jin X. Goh ◽  
Damian R. Murray
Keyword(s):  
Social Behavior ◽  
Sexual Attitudes ◽  
Experimental Manipulation ◽  
Sexual Relationships ◽  
Experimental Results ◽  
Acute Disease ◽  
Short Term ◽  
Attitudes And Behaviors ◽  
The Relationship ◽  
Sexual Promiscuity

How does disease threat influence sexual attitudes and behaviors? Although research on the influence of disease threat on social behavior has grown considerably, the relationship between perceived disease threat and sexual attitudes remains unclear. The current preregistered study (analyzed N = 510), investigated how experimental reminders of disease threat influence attitudes and anticipated future behaviors pertaining to short-term sexual relationships, using an ecologically valid disease prime. The central preregistered prediction was that experimental manipulation of disease threat would lead to less favorable attitudes and inclinations toward sexual promiscuity. Results were consistent with this preregistered prediction, relative to both a neutral control condition and a non-disease threat condition. These experimental results were buttressed by the finding that dispositional variation in worry about disease threat predicted less favorable attitudes and inclinations toward short-term sexual relationships. This study represents the first preregistered investigation of the implications of acute disease threat for sexual attitudes.

Effect of Composite Master Alloy on Mechanical Properties and Electrochemical Corrosion of ZL101 Alloy

2013 ◽  
Vol 749 ◽  
pp. 407-413
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Ji Ping Ren ◽  
Min Peng ◽  
Shi Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Grain Refinement ◽  
Master Alloy ◽  
Mass Fraction ◽  
Electrochemical Corrosion ◽  
Corrosion Performance ◽  
Obvious Effect ◽  
Mechanical Properties And Corrosion

The mechanical properties and corrosion performances of the ZL101 alloy modified by the composite master alloy were investigated. The results showed that the master alloy had not only obvious effect of grain refinement, but also a significant role in refining dendrite grain of ZL101 alloy. The grain size decreased dramatically from 150μm to 62μm when the addition of composite master alloy is up to 0.5%(mass fraction) and the temperature is 720 for 30 minutes,. Its tensile strength and elongation increased by 27% and 42% respectively. The grain refinement of ZL101 alloy decreased its corrosion performance. The morphology of Si changed into globular from needle modified by NaF, instead of AlTiB.

Research on Paper Whiteness Based on Visual Comfort

2013 ◽  
Vol 295-298 ◽  
pp. 543-546
Author(s):  
Zhi Jian Li ◽  
Nuo Li
Keyword(s):  
Negative Impact ◽  
Experimental Results ◽  
Reading Process ◽  
Visual Comfort ◽  
Visual Fatigue ◽  
The Relationship

High whiteness paper is likely to cause visual fatigue. The relationship between whiteness and visual comfort is studyed by adopting the form of a combination of presentation reading and questionnaires. The experimental results show that, during the reading process, the higher of paper whiteness, the greater the chance of looked up, eye rubbing, and other little tricks, at the same time, the easier inattentive, have a negative impact on reading effect.

Sign in / Sign up

Export Citation Format

Share Document