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Online since: April 2016
Authors: Vojtěch Kostiha, Đorđe Čairović, Petr Štěpánek, František Girgle
The matters of confined element is the formation of tri-axial state of stress, which causes an improvement in physical-mechanical properties of strengthened material.
Factors influencing the efficiency of this method of strengthening – FRP confining.
From the above mentioned, it is obvious that the efficiency of strengthening by confinement is determined by the properties and behavior of strengthening material (mechanical properties, number and orientation of fabric layers, the dislocation (placement) of strengthening elements along the height, etc.) as well as by the geometrical parameters of strengthened element (cross-sectional shape, surface characteristics, slenderness ratio, etc.).
(It should not to be set properties of dry fibers of fabric, which achieve significantly higher values.
For the purposes of the experimental verification, it was necessary to determine these properties precisely.
Factors influencing the efficiency of this method of strengthening – FRP confining.
From the above mentioned, it is obvious that the efficiency of strengthening by confinement is determined by the properties and behavior of strengthening material (mechanical properties, number and orientation of fabric layers, the dislocation (placement) of strengthening elements along the height, etc.) as well as by the geometrical parameters of strengthened element (cross-sectional shape, surface characteristics, slenderness ratio, etc.).
(It should not to be set properties of dry fibers of fabric, which achieve significantly higher values.
For the purposes of the experimental verification, it was necessary to determine these properties precisely.
Online since: September 2011
Authors: Yan Mei Li, Si Feng Zhang, Xiu Guang Song, Kai Yao
By adopting the similar model test and embedding the strain brick at each interfaces of inner bond section, the interface mechanical properties under step loading were systematically studied.
The shear stress distribution pattern of all interfaces within the inner bond section and the shear stress evolution regularity under external loading are two key factors that influence the structure design of geotechnical prestressed anchorage structures.
In addition, the actual monitoring data demonstrate that the prestressed force is not stable after the tension, which is in the constantly change state because of the influence of some factors such as rock creep, rod body slack, reinforcement construction and others.
Especially during the long-term operation period of prestressed anchor structure, there will present the cyclic loading mode because of the influence of temperature, rainfall and other factors.
Magnifying the size of grouting body with no change of other parameters in the model would not affect the shear stress distribution of anchor segments.
The shear stress distribution pattern of all interfaces within the inner bond section and the shear stress evolution regularity under external loading are two key factors that influence the structure design of geotechnical prestressed anchorage structures.
In addition, the actual monitoring data demonstrate that the prestressed force is not stable after the tension, which is in the constantly change state because of the influence of some factors such as rock creep, rod body slack, reinforcement construction and others.
Especially during the long-term operation period of prestressed anchor structure, there will present the cyclic loading mode because of the influence of temperature, rainfall and other factors.
Magnifying the size of grouting body with no change of other parameters in the model would not affect the shear stress distribution of anchor segments.
Online since: February 2018
Authors: Poornesh Kumar Chaturvedi, Harendra Kumar Narang, Atul Kumar Sahu
The Surface roughness intensifies the appearance of the product and also impacts on the other surface properties such as reflectivity, lubricant transport, ability to weld, adhesion and mechanical properties due to strain localization [1].
There are number of factors that influence the Material Removal Rate and surface roughness like machining parameters, cutting tool material properties, work piece material properties, cutting conditions etc.
Based on L9 orthogonal array 9 sets of experiment with 3 level and 3 factors are conducted and are shown in Table1.
Three Factors and Three levels of Process Parameters.
Ince, Optimisation of parameters affecting surface roughness of Co28Cr6Mo medical material during CNC lathe machining by using the Taguchi and RSM methods, Measurement. 78 (2016) 120-128
There are number of factors that influence the Material Removal Rate and surface roughness like machining parameters, cutting tool material properties, work piece material properties, cutting conditions etc.
Based on L9 orthogonal array 9 sets of experiment with 3 level and 3 factors are conducted and are shown in Table1.
Three Factors and Three levels of Process Parameters.
Ince, Optimisation of parameters affecting surface roughness of Co28Cr6Mo medical material during CNC lathe machining by using the Taguchi and RSM methods, Measurement. 78 (2016) 120-128
Online since: July 2017
Authors: Wilfrido Martínez Molina, Hugo Luis Chávez-García, Elia Mercedes Alonso Guzmán, Judith Alejandra Velázquez Perez, Rosalía Ruiz Ruiz
The way a mortar is affected by these degradation factors is a function related to the mortar characteristics, and it depends on the type and properties of the cementing agents, on the aggregate, on the quantity of water of the kneaded one, on its permeability, on the capacity of water absorption for capillarity [5-6], on the water ingestion [7-8], and on the presence of additives and on cure conditions [9-10].
The carbonation changes the mortar microstructure, not only enhances the mechanical properties, but it also affects the porous structure and consequently the characteristics of the water transportation [14].
When designing material for determined applications, various factors must be taken into consideration.
The material has to acquire minimal physical and mechanical properties outlined in the construction existing regulations.
Alvarez, Mechanical properties of masonry repair dolomitic lime-based mortars, Cem.
The carbonation changes the mortar microstructure, not only enhances the mechanical properties, but it also affects the porous structure and consequently the characteristics of the water transportation [14].
When designing material for determined applications, various factors must be taken into consideration.
The material has to acquire minimal physical and mechanical properties outlined in the construction existing regulations.
Alvarez, Mechanical properties of masonry repair dolomitic lime-based mortars, Cem.
Online since: April 2004
Authors: Young Doo Kwon, W.K. Choi, Hyun Wook Kwon, H.S. Choo
Choo2
1 School of Mechanical Engineering, Kyungpook National University, Daegu, Korea
ydkwon@knu.ac.kr
2
Research Assistant, Kyungpook National University, Daegu, Korea
Keywords: Center Segregation, HAZ(Heat Affected Zone), Temperature Distribution,
Phase Distribution, Groove Type, Groove Angle
ABSTRACT
The time-dependent distributions of temperature and stresses in a box-column welded from ultra
thick plates with a center segregation were analyzed using the commercial finite element package
SYSWELD+ for several types and angles of groove.
The thermal properties, i.e. conductivity and specific heat, were found to be temperature dependent, plus the effects arising from a phase change, convection, and radiation were also taken into account. 1.
However, high-heat input welding enlarges the HAZ(Heat Affected Zone), which changes the micro-structure of the base metal and produces more residual stress.
Temperature boundary condition for 2-D for different welding velocities thermo-mechanical coupled analysis Figure 2 shows the temperature histories of three welding velocities.
These x-x directional stresses were the most important factors in relation to lamellar tearing that appeared at the center segregation.
The thermal properties, i.e. conductivity and specific heat, were found to be temperature dependent, plus the effects arising from a phase change, convection, and radiation were also taken into account. 1.
However, high-heat input welding enlarges the HAZ(Heat Affected Zone), which changes the micro-structure of the base metal and produces more residual stress.
Temperature boundary condition for 2-D for different welding velocities thermo-mechanical coupled analysis Figure 2 shows the temperature histories of three welding velocities.
These x-x directional stresses were the most important factors in relation to lamellar tearing that appeared at the center segregation.
Online since: December 2012
Authors: Li Bing Jin, De Cai Chen, Ji Peng Qi
Various factors affecting the shear strength of UPSFRCB, such as steel fiber, prestress and shear-span to depth ratio were analyzed.
Tab. 1: Mixing proportions of concrete (1m3) Group Volume ratio of steel fiber Cement (kg) Water (kg) Sand (kg) Gravel (kg) Steel fiber (kg) Admixture (kg) Sand ratio W/C A 1.0% 455 200 990 914 78 2.05 52% 0.44 B 0% 410 180 726 1184 0 2.05 38% 0.44 Tab. 2: Size, material properties, test results of shear strength of test beams Beam No. b×h×h0 (mm) Shear span ratio φf (%) lf /df ffcu or fcu (MPa) NP1 (kN) Vfu / Vu (kN) A-1.5-1 150×300×265 1.5 1.0 50 40.2 142.3 200.0 A-1.5-2 150×300×265 1.5 1.0 50 40.2 178.4 213.5 A-2.0-1 150×300×265 2.0 1.0 50 40.2 145.7 161.5 A-2.0-2 150×300×265 2.0 1.0 50 40.2 141.8 167.0 B-1.5-1 150×300×265 1.5 0 0 40.0 146.1 174.0 B-1.5-2 150×300×265 1.5 0 0 40.0 148.8 161.5 B-2.0-1 150×300×265 2.0 0 0 40.0 145.3 138.5 B-2.0-2 150×300×265 2.0 0 0 40.0 153.4 154.5 (Where φf , lf and df are volume ratio, length and equivalent diameter of steel fiber respectively .)
The influence factors of shear capacity on diagonal section include prestress, shear span ratio, steel fiber, stirrups and so on.
Fiber reinforced concrete and bonding properties of existing concrete, Beijing: Science Press, 2008.
Mechanical properties of prestressed steel fiber reinforced concrete simple- supported beam [D], Kunming: Kunming University of Science and Technology, 2002
Tab. 1: Mixing proportions of concrete (1m3) Group Volume ratio of steel fiber Cement (kg) Water (kg) Sand (kg) Gravel (kg) Steel fiber (kg) Admixture (kg) Sand ratio W/C A 1.0% 455 200 990 914 78 2.05 52% 0.44 B 0% 410 180 726 1184 0 2.05 38% 0.44 Tab. 2: Size, material properties, test results of shear strength of test beams Beam No. b×h×h0 (mm) Shear span ratio φf (%) lf /df ffcu or fcu (MPa) NP1 (kN) Vfu / Vu (kN) A-1.5-1 150×300×265 1.5 1.0 50 40.2 142.3 200.0 A-1.5-2 150×300×265 1.5 1.0 50 40.2 178.4 213.5 A-2.0-1 150×300×265 2.0 1.0 50 40.2 145.7 161.5 A-2.0-2 150×300×265 2.0 1.0 50 40.2 141.8 167.0 B-1.5-1 150×300×265 1.5 0 0 40.0 146.1 174.0 B-1.5-2 150×300×265 1.5 0 0 40.0 148.8 161.5 B-2.0-1 150×300×265 2.0 0 0 40.0 145.3 138.5 B-2.0-2 150×300×265 2.0 0 0 40.0 153.4 154.5 (Where φf , lf and df are volume ratio, length and equivalent diameter of steel fiber respectively .)
The influence factors of shear capacity on diagonal section include prestress, shear span ratio, steel fiber, stirrups and so on.
Fiber reinforced concrete and bonding properties of existing concrete, Beijing: Science Press, 2008.
Mechanical properties of prestressed steel fiber reinforced concrete simple- supported beam [D], Kunming: Kunming University of Science and Technology, 2002
Online since: April 2022
Authors: Masaharu Shiratani, Pankaj Attri, Kunihiro Kamataki, Kazunori Koga, Naho Itagaki, Fadzai Lesley Chawarambwa, Tika Erna Putri
PEDOT:PSS is a very successful conducting polymer due to its interesting properties like high conductivity, high transmittance in the visible light range, good electrochemical properties, and good thermal stability [15,16].
Optical properties and Raman Spectra of the counter electrode.
Photovoltaic properties of the DSSCs.
Thicker films exhibit better electrochemical properties as compared to thinner films.
However, thicker platinum polymer counter electrode films have reduced transmittance, ultimately affecting their performance in bifacial applications.
Optical properties and Raman Spectra of the counter electrode.
Photovoltaic properties of the DSSCs.
Thicker films exhibit better electrochemical properties as compared to thinner films.
However, thicker platinum polymer counter electrode films have reduced transmittance, ultimately affecting their performance in bifacial applications.
Online since: September 2018
Authors: D.G. Piliptsou, Alexander V. Rogachev, Alexander S. Rudenkov, Ekaterina Kulesh, Alexander Luchnikov
The influence of the architecture of multilayer metal-carbon coatings, the nature of individual metallic layers (Ti, Cu), heat treatment parameters on their microhardness, the level of internal stresses and tribotechnical properties are determined.
Introduction The structure and properties of multilayer metal-carbon film coatings obtained by deposition in vacuum from plasma by arc discharge are largely determined by technological factors of their formation [1–4].
It gave the opportunity to implement the idea of the catalytic effect of metals on the phase and chemical composition of a carbon layer to change the structure and properties of the coating.
Conclusion The research of the structural and physical-mechanical properties of metal-carbon coatings shows that thermal annealing promotes graphitization of the carbon layer and the increase in the size of clusters of graphite in the coating, which reduces its microhardness.
Rudenkov, Influences of pulse frequency on the structure and anti-corrosion properties of the a-C:Cr films, Applied Surface Science 351 (2015) 1197-1203, doi: 10.1016/j.apsusc.2015.05.157
Introduction The structure and properties of multilayer metal-carbon film coatings obtained by deposition in vacuum from plasma by arc discharge are largely determined by technological factors of their formation [1–4].
It gave the opportunity to implement the idea of the catalytic effect of metals on the phase and chemical composition of a carbon layer to change the structure and properties of the coating.
Conclusion The research of the structural and physical-mechanical properties of metal-carbon coatings shows that thermal annealing promotes graphitization of the carbon layer and the increase in the size of clusters of graphite in the coating, which reduces its microhardness.
Rudenkov, Influences of pulse frequency on the structure and anti-corrosion properties of the a-C:Cr films, Applied Surface Science 351 (2015) 1197-1203, doi: 10.1016/j.apsusc.2015.05.157
Online since: February 2014
Authors: Rong Liu, Tong Xue, Shi Min Zhai
The development of mine rescue robot for inspection is of great significance to improve coal mine production safety and reduce the loss of state property and people's life.
By formula (1) and (2), it can be obtained that the height of the obstacle, the length of the articulated arm, the center of the articulated arm’s gravity place, the length of the robot’s body, the center of the body’s gravity place, the radius of the driving wheel, the driving torque of the articulated arm and the properties of the contact surface are all related to the first step.
Length changes in articulated arm of these factors affect the first step the most complexly.
As the other factors remain unchanged, the driving torque of the articulated arm is provided M, the approximations are:
By the formula (4) and (5) it can be seen that the center of gravity position of the robot and the radius of the main track wheels are the main factors affecting the obstacle crossing.
By formula (1) and (2), it can be obtained that the height of the obstacle, the length of the articulated arm, the center of the articulated arm’s gravity place, the length of the robot’s body, the center of the body’s gravity place, the radius of the driving wheel, the driving torque of the articulated arm and the properties of the contact surface are all related to the first step.
Length changes in articulated arm of these factors affect the first step the most complexly.
As the other factors remain unchanged, the driving torque of the articulated arm is provided M, the approximations are:
By the formula (4) and (5) it can be seen that the center of gravity position of the robot and the radius of the main track wheels are the main factors affecting the obstacle crossing.
Online since: September 2012
Authors: Liang Sheng Wu, Cheng Chun Chu, Yuan Yuan Li, Yi Chuan Xiao, Bao Zhu Zhang
It will seriously affect the accuracy and reliability of machine tools working.
Sub-sections of beams composed of its properties, especially its dynamic characteristics than the overall beam will be very different, its mechanical impedance and frequency response function will be very different.
(2-6) Affect the accuracy of the accidental results there are many factors, even if exact single degree of freedom system[3].
Combined with appropriate medium between the surface can significantly improve the joint surface stiffness and damping characteristics. adding media material to improve the mechanical properties of high vibration resistance in the design of modern machinery and equipment in a wide range of applications.
The factors effect the dynamic of the joint surface, such as bolt pretension pressure, media and so on.
Sub-sections of beams composed of its properties, especially its dynamic characteristics than the overall beam will be very different, its mechanical impedance and frequency response function will be very different.
(2-6) Affect the accuracy of the accidental results there are many factors, even if exact single degree of freedom system[3].
Combined with appropriate medium between the surface can significantly improve the joint surface stiffness and damping characteristics. adding media material to improve the mechanical properties of high vibration resistance in the design of modern machinery and equipment in a wide range of applications.
The factors effect the dynamic of the joint surface, such as bolt pretension pressure, media and so on.