scholarly journals Influence of furniture exploitation on the bending strength of final mountable-dismountable corner joints

2021 ◽  
Vol 1208 (1) ◽  
pp. 012029
Author(s):  
Marija Krstev ◽  
Ivana Antovska ◽  
Elena Jevtoska ◽  
Gjorgi Gruevski
Keyword(s):  
Bending Strength ◽  
European Standard ◽  
Reference Test ◽  
Research Results ◽  
The Stability

Abstract The aim of the researches presented in the paper is to show how the exploitation of furniture affect the strength of its connectors, more precisely the bending strength of the final corner dismountable joints for designed furniture – office desk. For studying this influence, 2 office desks were made (from chosen material OSB panels), joined by dismountable connectors, and also from the same material and the same type of connectors, reference test fixtures were made and their bending strength was the value of comparison. Office desks were tested according to European Standard for determining the stability of the structure (EN 527-3:2003 E) and that was simulated exploration of furniture. After that, the final corner compositions were cut off, and its bending strength was compared with the reference test fixtures strength. The research results showed that the exploiting of dismountable furniture has not a significant impact on their compositions strength.

scholarly journals Utilization of Birch Bark as an Eco-Friendly Filler in Urea-Formaldehyde Adhesives for Plywood Manufacturing

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 511
Author(s):  
Roman Réh ◽  
Ľuboš Krišťák ◽  
Ján Sedliačik ◽  
Pavlo Bekhta ◽  
Monika Božiková ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Formaldehyde Emission ◽  
Birch Bark ◽  
Gravimetric Analysis ◽  
European Standard ◽  
Scanning Calorimetry ◽  
Wood Processing ◽  
Fagus Sylvatica L ◽  
Positive Effect

The potential of using ground birch (Betula verrucosa Ehrh.) bark as an eco-friendly additive in urea-formaldehyde (UF) adhesives for plywood manufacturing was investigated in this work. Five-ply plywood panels were fabricated in the laboratory from beech (Fagus sylvatica L.) veneers bonded with UF adhesive formulations comprising three addition levels of birch bark (BB) as a filler (10%, 15%, and 20%). Two UF resin formulations filled with 10% and 20% wheat flour (WF) were used as reference samples. The mechanical properties (bending strength, modulus of elasticity and shear strength) of the laboratory-fabricated plywood panels, bonded with the addition of BB in the adhesive mixture, were evaluated and compared with the European standard requirements (EN 310 and EN 314-2). The mechanical strength of the plywood with the addition of BB in the adhesive mixture is acceptable and met the European standard requirements. Markedly, the positive effect of BB in the UF adhesive mixture on the reduction of formaldehyde emission from plywood panels was also confirmed. Initially, the most significant decrease in formaldehyde release (up to 14%) was measured for the plywood sample, produced with 15% BB. After four weeks, the decrease in formaldehyde was estimated up to 51% for the sample manufactured with 20% BB. The performed differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and derivative thermogravimetry (DTG), also confirmed the findings of the study. As this research demonstrated, BB as a waste or by-product of wood processing industry, can be efficiently utilized as an environmentally friendly, inexpensive alternative to WF as a filler in UF adhesive formulations for plywood manufacturing.

The Stability Control of Soft Soil Foundations of Urban Roads According to the Surface Subsidence Monitoring Data

2013 ◽  
Vol 859 ◽  
pp. 222-227
Author(s):  
Hong Jun Liu ◽  
Jin Hua Tan ◽  
Xue Wen Su ◽  
Hao Wu
Keyword(s):  
Soft Soil ◽  
Stability Control ◽  
Surface Subsidence ◽  
Monitoring Data ◽  
Research Results ◽  
The Road ◽  
Future Design ◽  
Left And Right ◽  
Soil Foundation ◽  
The Stability

Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.

scholarly journals Hydraulic Tests and Interpretation of Test Data for Reno Mattresses in Open Channel Flow

2021 ◽  
Vol 930 (1) ◽  
pp. 012025
Author(s):  
P D Pietro ◽  
M Lelli ◽  
A Rahman ◽  
Serkandi
Keyword(s):  
Soil Erosion ◽  
Control Systems ◽  
Soil Layer ◽  
Erosion Control ◽  
Wire Mesh ◽  
Unit Weight ◽  
Research Results ◽  
Colorado State University ◽  
Soil Erosion Control ◽  
The Stability

Abstract The efficacy of erosion control systems depends on preventing soil loss underneath and maintaining its integrity under the effects of the water flow. The paper presents the research results at the Colorado State University on the performance of double twisted wire mesh products, known as Reno Mattresses, used as soil erosion control systems. Mattresses were subjected to various flow conditions on a 10 m long flume placed on a soil layer. The performance against erosion was evaluated by assessing the effect of the stone motion inside the mattress combined with the condition of incipient soil erosion underneath, in relationship to the mattress thickness, the filling stone properties, and under variable hydraulic flow regimes. At the same time, confirming the stability obtained using the conventional tractive force design approach, the research results allowed to introduce a new performance limit based on incipient soil erosion underneath the revetment. Based on the research results, the authors propose to express the shear resistance of mattresses used as soil erosion control systems as a function of the filling stones’ size, uniformity, unit weight, mattress thickness, and the presence of vertical strengthening elements.

scholarly journals Effect of Slip Surface’s Continuity on Slope Dynamic Stability Based on Infinite Slope Model

Mathematics ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Chuanzheng Liu ◽  
Gang Wang ◽  
Wei Han
Keyword(s):  
Dynamic Stability ◽  
Stress Wave ◽  
Safety Factor ◽  
Slip Surface ◽  
Great Influence ◽  
Stress Wave Propagation ◽  
Surface Model ◽  
Infinite Slope ◽  
Research Results ◽  
The Stability

The slip surface is an important control structure surface existing in the landslide. It not only directly affects the stability of the slope through the strength, but also affects the stress field by affecting the propagation of the stress wave. Many research results have been made on the influence of non-continuous stress wave propagation in rock and soil mass and the dynamic response to seismic slopes. However, the effect of the continuity of the slip surface on the slope dynamic stability needs further researches. Therefore, in this paper, the effect of slip surface on the slope’s instantaneous safety factor is analyzed by the theoretical method with the infinite slope model. Firstly, three types of slip surface model were established, to realize the change of sliding surface continuity in the infinite slope. Then, based on wave field analysis, the instantaneous safety factor was used to analyze the effect of continuity of slip surface. The results show that with the decreasing of slip surface continuity, the safety factor does not simply increase or decrease, and is related to slope features, incident wave and continuity of slip surface. The safety factor does not decrease monotonically with the increasing of slope angle and thickness of slope body. Moreover, the reflection of slope surface has a great influence on the instantaneous safety factor of the slope. Research results in this paper can provide some references to evaluate the stability of seismic slope, and have an initial understanding of the influence of structural surface continuity on seismic slope engineering.

3Y-TZP/Si2N2O Composite Obtained by Pressureless Sintering

2008 ◽  
Vol 591-593 ◽  
pp. 415-422
Author(s):  
Carlos A. Xavier Santos ◽  
Motozo Hayakawa ◽  
José Carlos Bressiani
Keyword(s):  
Room Temperature ◽  
Bending Strength ◽  
Sintered Material ◽  
Silicon Oxynitride ◽  
Atmospheric Conditions ◽  
Sintering Aids ◽  
Pressure System ◽  
The Matrix ◽  
Considerable Resistance ◽  
The Stability

Y-TZP presents excellent properties at room temperature but these properties decrease as the temperature increases. This paper studies the behavior 20vol%Si3N4-SiC when added in YTZP matrix and heated under no pressure system. Al2O3 and Y2O3 were used to maintain the stability of the matrix and as sintering aids. The addition of Si3N4 and SiC in a Y-TZP matrix leads to formation of silicon oxynitride and it increases the mechanical properties like toughness and hardness. The mixture was milled and molded by CIP. Samples were heated at 1500°C, 1600°C and 1700°C for 2h without pressure under atmospheric conditions in bed-powders of Si3N4. Samples were characterized by XRD. Density, hardness, toughness, bending strength were measured. The structure of the material was observed in SEM/EPMA to verify the distribution of the materials in the composite. The formation of Si2N2O was observed in the sintered material and it showed an increment of both hardness and toughness as temperature increases. The samples presented considerable resistance of oxidation at 1000°C.

Influence of Structural Plane in Similar Soil Surrounding Rock on Excavation Stability

2010 ◽  
Vol 168-170 ◽  
pp. 1318-1324
Author(s):  
Qiang Chen ◽  
Wei Tao Chen ◽  
Guo Wei Meng
Keyword(s):  
Numerical Calculation ◽  
Surrounding Rock ◽  
Disintegration Time ◽  
Structural Plane ◽  
Research Results ◽  
Tunnel Stability ◽  
Excavation Stability ◽  
Shearing Strength ◽  
The Stability ◽  
Similar Soil

Lots of primary or secondary structural planes in similar soil surrounding rock are the main difference with Quaternary soil surrounding rock, but the particularity isn’t considered in the analysis of tunnel stability. The fact, which similar soil surrounding rock has most weak structural planes, is testified by engineering examples. The influence of structural plane in similar soil surrounding rock on excavation stability was analyzed through combining theory with disintegration test and numerical calculation. The research results show that there are a lot of structural planes in similar soil surrounding rock. The angle between structural planes and tunnel axes and shearing strength of structural planes control the stability of tunnel. Disintegration time of soil is shortened due to structural planes. On a certain condition, structural planes can induce local collapse in soil surrounding rock while excavating.

Investigation on the Tap-Hole Clay under Thermal Processing

2009 ◽  
Vol 79-82 ◽  
pp. 2099-2102 ◽  
Author(s):  
Shi Ling Yang ◽  
Jian Hua Zhang ◽  
Ying Dong ◽  
Shi Bin Sun ◽  
Ping Cui
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Microstructure Evolution ◽  
Thermal Processing ◽  
Bending Strength ◽  
Practical Application ◽  
Research Results ◽  
Steel Corporation ◽  
Increasing Temperature

Taking the waterless tap-hole clay in the 1750m3 blast furnace of Jinan Steel Corporation for example, thermal processing at temperatures ranging from 200°C to 1400°C has been performed. The authors systematically investigated the main features of the clay such as bending strength, compressive strength, porosity and density after thermal processing, the microstructure evolution of the clay with increasing temperature were also studied in brief. Research results provide theoretical information for the practical application of tap-hole clay in the blast furnace and are also helpful for understanding the possible property transition of the tap-hole clay in the tap-hole.

scholarly journals Assessment of the stability and loading indicators of two-axle mine cars and rail tracks

2020 ◽  
Vol 168 ◽  
pp. 00044
Author(s):  
Volodymyr Hovorukha ◽  
Todor Zhelyazov
Keyword(s):  
Transport Systems ◽  
Movement Speed ◽  
Rolling Stock ◽  
Research Results ◽  
Rail Track ◽  
Regulatory Documents ◽  
Rail Vehicles ◽  
The Stability ◽  
Technical Solutions ◽  
Track Irregularities

The paper presents the research results of the stability and loading of the two-axle mine cars and rail tracks with various design for calculation schemes construction of transport systems of underground rail haulage. The dependences of changes in loading, stability and operation safety of rolling stocks from the parameters of irregularities, curvature radii of the rail track and the movement speed of rolling stocks at various technical solutions of the transport system, have been studied. The research results of the interaction between the two-axle mine cars and rail track with the gauge of 750 mm for underground rail haulage are presented. The parameters have been determined of the rail track irregularities in the horizontal and vertical planes, which cause the highest values of vertical and horizontal loads, acting on the rail track and the two-axle rolling stock. The recommendations are proposed for improving the study of the rail vehicles and regulatory documents development for the construction and operation of the track structure. The results can be applied for the underground rail haulage when creating the new vehicles for mines.

scholarly journals Comprehensive Analysis of Stability of Coal Seam Composite Roof Based on Analytic Hierarchy Process

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xianyu Xiong ◽  
Jun Dai ◽  
Xin Wang
Keyword(s):  
Analytic Hierarchy Process ◽  
Structural Stability ◽  
Bending Strength ◽  
Complex Structure ◽  
Cohesive Force ◽  
Influence Coefficient ◽  
Analytic Hierarchy ◽  
Roof Structure ◽  
The Stability ◽  
Hierarchy Process

The composite roof structure of coal roadway is complex, and its stability is related to lithology of strata, strata thickness, number of strata, strata location, and interlayer cohesive force. Based on a simplified model of the composite roof structure, simulation test, analytic hierarchy process (AHP), and Matlab, programs are employed to comprehensively analyze the structural stability of roofs. The structural stability of the composite roof is demonstrated to decrease with the lithology of strata, strata thickness, and interlayer cohesive force and increase in number of strata and distance of hard-and-thick strata from the roadway. The decreasing order of influence of these factors on the composite roof structure is as follows: lithology of strata, strata thickness, number of strata, strata location, and interlayer cohesive force. Lithology of strata is the main factor affecting stability. The bending strength decreases with the increase in number of strata, and the influence of strata position on stability decreases from the first layer to the fourth layer. According to the AHP, an expression for the comprehensive influence coefficient (k) for the stability of the composite roof structure is proposed, and the surrounding rocks are divided into three levels using this equation: grade I with 0.7 < k < 1 (stable), grade II with 0.4 < k < 0.7 (slightly stable), and grade III with 0 < k < 0.4 (unstable). A scientific basis to evaluate the stability and control of the composite roof of a complex structure is thus provided.

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