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Online since: September 2014
Authors: Bo Hou, A.H. van den Boogaard, Emin Semih Perdahcioglu
The current work therefore focuses on detailing the underlying mechanical principles that lead to an explanation of the formability enhancement as a function of process and material properties.
In order to take all these factors into account, detailed 3D solid element FE-simulations of ASBT is performed to study the physical mechanism of enhanced formability under stretch-bending.
The effect of these factors on the stretch-bending formability is investigated and summarized in the following.
This shows that the punch radius as well as material properties have a significant role on the strain path evolution during stretch bending.
The underlying physical factors are bending and thickness stresses, which have a significant effect on the major stress gradient and non-linear strain path.
In order to take all these factors into account, detailed 3D solid element FE-simulations of ASBT is performed to study the physical mechanism of enhanced formability under stretch-bending.
The effect of these factors on the stretch-bending formability is investigated and summarized in the following.
This shows that the punch radius as well as material properties have a significant role on the strain path evolution during stretch bending.
The underlying physical factors are bending and thickness stresses, which have a significant effect on the major stress gradient and non-linear strain path.
Online since: October 2015
Authors: Marián Kučera, Jindřich Pavlů, Michaela Hnilicová
The experiment lasted for one year and five oil samples were taken during this period and evaluated their qualitative properties.
These might relate to important chemical and physical properties of the lubricant such its viscosity.
Viscosity Viscosity is one of the most important properties of hydraulic oil.
Since all hydraulic fluids have some inherent acidic properties any increase in TAN must be compared to the new oil value as a baseline.
FTIR analysis Very important factor when oil is in operation is its quality.
These might relate to important chemical and physical properties of the lubricant such its viscosity.
Viscosity Viscosity is one of the most important properties of hydraulic oil.
Since all hydraulic fluids have some inherent acidic properties any increase in TAN must be compared to the new oil value as a baseline.
FTIR analysis Very important factor when oil is in operation is its quality.
Online since: July 2008
Authors: Andreas N. Alexandrou, Georgios C. Georgiou, Nicholas Constantinou
Alexandrou1,a
, Nicholas Constantinou1 and Georgios Georgiou2,b
1
Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
2
Department of Mathematics and Statistics, University of Cyprus, Nicosia, Cyprus
a
andalexa@ucy.ac.cy, bgeorgios@ucy.ac.cy
Keywords: buildup; aging; coherency parameter; Herschel-Bulkley fluid; shear banding; shear
rejuvenation; structural parameter; suspensions; thixotropy; yield stress
Abstract.
The suspension is described by the Herschel-Bulkley model with time-dependent properties.
Since Re is a multiplying factor we only obtain results for 1Re = .
Apelian, "Transient Flow Characteristics and Properties of Semi-solid Aluminum Alloy A356," 8 th International Conference on SemiSolid Processing of Metals and Alloys, September 21-23, 2004.
(Ed.), Metal & Ceramic Matrix Composites: Processing Modeling & Mechanical Behavior, The Minerals, Metals and Materials Society, 337-350, (1990).
The suspension is described by the Herschel-Bulkley model with time-dependent properties.
Since Re is a multiplying factor we only obtain results for 1Re = .
Apelian, "Transient Flow Characteristics and Properties of Semi-solid Aluminum Alloy A356," 8 th International Conference on SemiSolid Processing of Metals and Alloys, September 21-23, 2004.
(Ed.), Metal & Ceramic Matrix Composites: Processing Modeling & Mechanical Behavior, The Minerals, Metals and Materials Society, 337-350, (1990).
Online since: January 2010
Authors: Frank Lüthen, Joachim Rychly, Rainer Bader, Birgit Finke, Karsten Schröder, Martin Polak, Gerold Lukowski, Uwe Walschus, Michael Schlosser, Andreas Ohl, Klaus Dieter Weltmann, Barbara Nebe
Such contradictorily adhesion
events could be triggered by surface properties.
These titanium surface functionalizations were found to have either an antimicrobial activity or cell-adhesive properties.
Thus, the physico-chemical properties of the implant surface like roughness, purity or a thin coating, affect the cellular response in vitro and in vivo.
Therefore, it is worthwhile to characterize coating properties in more detail.
All in all, surface properties of PPAAm-Cu PIII-TiP and PPAAm-TiP seem to be similar to a large extent.
These titanium surface functionalizations were found to have either an antimicrobial activity or cell-adhesive properties.
Thus, the physico-chemical properties of the implant surface like roughness, purity or a thin coating, affect the cellular response in vitro and in vivo.
Therefore, it is worthwhile to characterize coating properties in more detail.
All in all, surface properties of PPAAm-Cu PIII-TiP and PPAAm-TiP seem to be similar to a large extent.
Online since: June 2014
Authors: Bo Lin Wu, Jun Chang Liu
Introduction
Alumina ceramics is widely used in many industries because of its high melting point, good hardness, electrical resistivity, chemical durability, and excellent mechanical property.
Betes [6,7] and many other researchers investigated the crystallographic behavior of spinel and mullite, etc, but they didn’t explore the relationship between crystallographic behavior and mechanical property.
Based on previous researches, I think each factor will influence the performance of the products when it reaches to the abrasion limit of alumina ceramics.
The ratio of CaO/MgO can affect the firing temperature and wear rate of the sample. 98 porcelain is of better wear resistance and lower firing temperature than 95 porcelain.
Influence of powder structure on processing and properties of advanced ceramics.
Betes [6,7] and many other researchers investigated the crystallographic behavior of spinel and mullite, etc, but they didn’t explore the relationship between crystallographic behavior and mechanical property.
Based on previous researches, I think each factor will influence the performance of the products when it reaches to the abrasion limit of alumina ceramics.
The ratio of CaO/MgO can affect the firing temperature and wear rate of the sample. 98 porcelain is of better wear resistance and lower firing temperature than 95 porcelain.
Influence of powder structure on processing and properties of advanced ceramics.
Online since: July 2006
Authors: Günter Gottstein, Mischa Crumbach, L. Neumann, R. Kopp
Introduction
For modelling a process chain to predict the final material properties, it is necessary to use
microstructural physics based models, since microstructure is the state variable of materials
properties.
The final goal was to predict microstructure evolution and resulting properties of Aluminum sheet.
For Aluminum sheet the crystallographic texture was identified as microstructural key issue governing the resulting sheet properties.
The mechanical properties of the final sheet were tested in uniaxial tension tests on specimens cut along different directions within the rolling plane, and by cup drawing.
On the other hand, also other parameters like friction and elastic properties seem to be equally important for the exact cup height prediction.
The final goal was to predict microstructure evolution and resulting properties of Aluminum sheet.
For Aluminum sheet the crystallographic texture was identified as microstructural key issue governing the resulting sheet properties.
The mechanical properties of the final sheet were tested in uniaxial tension tests on specimens cut along different directions within the rolling plane, and by cup drawing.
On the other hand, also other parameters like friction and elastic properties seem to be equally important for the exact cup height prediction.
Online since: July 2021
Authors: Serhii Pozdieiev, Olena Borsuk, Olha Nekora, Oleksandr Nuianzin
Scheme of application of mechanical load to the steel beam and fastening conditions.
The magnitude of the distributed load is taken by the load factor m = 0.2.
Using the mathematical apparatus and mathematical descriptions of the properties of materials described in [1], the time of influence of the standard temperature of the fire is calculated, at which the flame retardant mineral wool cladding detaches from the beam. 3.
Using the mathematical apparatus and mathematical descriptions of the properties of the materials contained in [1], the limit of fire resistance is calculated, as shown in fig. 3.
To do this, in the future a system of correction factors should be developed to reduce the value of the limit of fire resistance due to the sudden destruction of fire protection systems.
The magnitude of the distributed load is taken by the load factor m = 0.2.
Using the mathematical apparatus and mathematical descriptions of the properties of materials described in [1], the time of influence of the standard temperature of the fire is calculated, at which the flame retardant mineral wool cladding detaches from the beam. 3.
Using the mathematical apparatus and mathematical descriptions of the properties of the materials contained in [1], the limit of fire resistance is calculated, as shown in fig. 3.
To do this, in the future a system of correction factors should be developed to reduce the value of the limit of fire resistance due to the sudden destruction of fire protection systems.
Online since: May 2012
Authors: Kun Peng Gu, Cheng Qi Wang
Introduction
Sulfate corrosion is one of the key factors for durability of concrete structure[1-4].
There are potential expansion property test method(P method) and soaked corrosion resistance test method(K method) in the GB/T 749-2008, ”test method for determing capability of resisting sulfate corrode of cement”.
Chemical composition and physical-mechanical characteristic of all kinds of cement are presented respectively in Table 1 and Table 2.
More over, cement is the key factor to sulfate resistance of cementitious material single doped fly ash which can’t improve sulfate resistance of cementitious material always[8].
Kumar Mehta: Concrete Structure, Properties and Materials(Prentice Hall prss, America,1991)
There are potential expansion property test method(P method) and soaked corrosion resistance test method(K method) in the GB/T 749-2008, ”test method for determing capability of resisting sulfate corrode of cement”.
Chemical composition and physical-mechanical characteristic of all kinds of cement are presented respectively in Table 1 and Table 2.
More over, cement is the key factor to sulfate resistance of cementitious material single doped fly ash which can’t improve sulfate resistance of cementitious material always[8].
Kumar Mehta: Concrete Structure, Properties and Materials(Prentice Hall prss, America,1991)
Online since: October 2023
Authors: Gracia M. Bruscas-Bellido, Sergio Benavent-Nácher, Jose V. Abellán-Nebot, Pedro Rosado-Castellano, Julio Serrano
In this sense, during last years the authors have identified many errors in the students’ tests due to the deficient assimilation of basic concepts from previous courses, such as physical concepts (torque, power, energy, etc.) or mathematical concepts (inequalities, use of exponential functions and logarithms, trigonometry, properties of statistical distributions, etc.), among others.
In fact, the authors have realized that many of the errors committed by the students in the manufacturing tests are mainly due to a poor assimilation of basic concepts from previous courses (e.g., physical concepts such as torque, power, energy; mathematical concepts such as inequalities, use of exponential functions and logarithms, trigonometry, properties of statistical distributions, etc.).
In [6], an extensive bibliographical review on this issue is presented, including a meta-analysis of numerous references and concluding that the prior knowledge is an excellent predictor of achievement after learning, but there is no consensus or convergence in the identification of the main factors of this influence.
In this sense, the work presented in [5] identifies some determining factors in prior knowledge to understand its effect on learning.
Another interesting example is presented in [8], focused on the teachers' previous knowledge and their experience, and the influence of these factors on the quality of teaching in the field of biology.
In fact, the authors have realized that many of the errors committed by the students in the manufacturing tests are mainly due to a poor assimilation of basic concepts from previous courses (e.g., physical concepts such as torque, power, energy; mathematical concepts such as inequalities, use of exponential functions and logarithms, trigonometry, properties of statistical distributions, etc.).
In [6], an extensive bibliographical review on this issue is presented, including a meta-analysis of numerous references and concluding that the prior knowledge is an excellent predictor of achievement after learning, but there is no consensus or convergence in the identification of the main factors of this influence.
In this sense, the work presented in [5] identifies some determining factors in prior knowledge to understand its effect on learning.
Another interesting example is presented in [8], focused on the teachers' previous knowledge and their experience, and the influence of these factors on the quality of teaching in the field of biology.
Online since: December 2010
Authors: Thomas Lampke, Matthias Hockauf, T. Halle, Martin F.X. Wagner, Kristin Hockauf
The conditions under investigation represent different stages of microstructural refinement as well as a ductility-optimized condition with superior crack growth properties, obtained by a combination of ECAP and aging.
The application of this concept shows a strong interaction of both parameters for all ECAP-processed conditions, where the ductility-optimized condition reveals superior FCP properties compared to the “as-processed” conditions.
A main focus lies on the correlation of the fatigue threshold with microstructural features and mechanical properties such as grain dimensions, yield stress, susceptibility of cyclic hardening, slip character and others.
Based on two necessary minimum conditions for crack growth, DK*th and K*max, which are considered as intrinsic material properties and are themselves a function of microstructure, environment, etc., this theory intentionally omits an explanation based on the extrinsic factor of crack closure.
In the near-threshold region, where crack propagation is strongly affected by the microstructure, grain size and, correspondingly, crack surface roughness are considered to be governing factors for both DKth as well as for its dependence on R.
The application of this concept shows a strong interaction of both parameters for all ECAP-processed conditions, where the ductility-optimized condition reveals superior FCP properties compared to the “as-processed” conditions.
A main focus lies on the correlation of the fatigue threshold with microstructural features and mechanical properties such as grain dimensions, yield stress, susceptibility of cyclic hardening, slip character and others.
Based on two necessary minimum conditions for crack growth, DK*th and K*max, which are considered as intrinsic material properties and are themselves a function of microstructure, environment, etc., this theory intentionally omits an explanation based on the extrinsic factor of crack closure.
In the near-threshold region, where crack propagation is strongly affected by the microstructure, grain size and, correspondingly, crack surface roughness are considered to be governing factors for both DKth as well as for its dependence on R.