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Analysis of the Influence of Microstructure Heterogeneity and Mechanical Properties of Welded Joint Constituents on Fracture Toughness for Plane Strain, KIc Ivica Čamagić1, a, Nemanja Vasić1, b, Zijah Burzić2, c, Aleksandar Sedmak3, d 1Faculty of Technical Sciences, Kosovska Mitrovica, 7 Kneza Miloša Street, Serbia 2Military Institute of Techniques, Belgrade, 15 Katanićeva Street, Serbia 3Faculty of Mechanical Engineering, Belgrade, 16 Kraljice Marije Street, Serbia aivica.camagic@pr.ac.rs, bnemanja.vasic@pr.ac.rs, czijah_burzic@rvkds.net, dasedmak@mas.bg.ac.rs Keywords: welded joint, crack, notch, fracture toughness under plane strain Abstract.
Welded joint, as an integral part of a structure, represents inhomogeneity by microstructure and mechanical properties, often by geometrical form, and by the stress field as well, which are affected by various factors as well as residual stresses after welding [1].
Experimental Determination of the Fracture Toughness, KIc Butt welded joint (2/3 X-weld) of Nionikral-70 low alloyed high strength steel was studied, in order to perceive more clearly the influence of microstructure heterogeneity and mechanical properties of welded joint on fracture toughness, KIc, under plane strain.
The influence of structure heterogeneity on the toughness properties of the welded joint components can be seen from the diagrams [7].
Values of the fracture mechanics parameters Specimen mark Critical J integral JIc, [kJ/m2] Critical stress intensity factor KIc, [MPa m1/2] BM-1 90,4 142,7 BM-2 94,3 145,8 WM-1 64,3 119,2 WM-2 61,5 116,6 HAZ-1 80,4 131,9 HAZ-2 74,9 127,3 Summary Heterogeneity of welded joint mechanical properties, or its components, can be clearly seen from the obtained values of fracture toughness under plane strain, KIc, determined indirectly by the critical JIc integral.

The rotor part is the core component of experimental system, which directly affects the mechanical properties of the experimental test capabilities and the stability of the system.
In consideration of the complicated factors of mechanical properties, the geometrical parameters of rotor, rotor speed and gyration radius of holes are taken as the optimizing objects, the particle swarm optimization strategy are proposed to optimize the rotor mechanical properties, then the testing capability and stability of the experimental system are improved.
Multi-objective optimization of the rotor mechanical properties parameters Mechanical property of the rotor is affected by various factors, which is a typical multi-objective optimization problem, the conflict exists in optimization goals.
The factors should be carried out through scientific analysis and selection, then the design variable can be selected which has a significant influence on the mechanical properties of the rotor, and can directly be controlled.
Constraints： 150≤x1≤25020≤x2≤50x32∙x4≥1500x1－x4>10 In the formula,，——long axis length of the ellipsoid ——short axis length of the ellipsoid ——Rotor speed ——gyration radius of hole ——Rotor extreme stress ——Rotor extreme strain ——Rotor moment of inertia Optimization strategy of the rotor mechanical properties The mechanical properties are affected significantly by the rotor geometry parameters, and the influence presents nonlinear, some factors on the mechanical properties of the rotor can be gotten through simulation experiments, but the influence of a number of factors becomes complicated, direct guidance can be hardly provided and calculation process is cumbersome and time-consuming.

Standard Eurocode 3: STN EN 1993-4-3 establishes the requirements for material properties of pipes and welds, associated with mechanical properties.
Introduction Structure and its construction elements are affected, besides the method of straining, by other factors such as material, its state and properties.
Integral part of material structure is the amount of irregularities and defects that affect material properties and thus its ability to withstand load.
Steel used for pipes must have adequate mechanical properties and must be suitable for welding.
Standard STN EN 1993-4-3: 2007 establishes the requirements for material properties of pipes and welds, associated solely with mechanical properties.

The experimental results show that the main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential.
Although the potentiostatic EIS can reveal surface properties of metals, it is not feasible to observe the surface in situ because the ECMP is a kinetic process.
Experimental All experiments were carried out on an simulated electrochemical mechanical polishing equipment [3,4].
Though both electrochemical reaction and mechanical abrasion are important factors in the Cu ECMP process, the main factor is the former causing the impedance dramatically decrease with the increase of the applied potential since the mechanical power obtained under different potential can be considered as a constant as mentioned above.
According to the single frequency EIS results, the main factor which affect the thickness of the oxide layer formed during ECMP process in alkali-based solutions is the applied potentials, the minor factor is the mechanical power.

The metallurgical properties and weld bead geometry and mechanical properties of the joints determine the quality of the joints.
Final equation in terms of coded factors: FZ=411.39-97.23*A-26.08*B-3.23*C, final equation in terms of actual factors: FZ=810.53-194.45*Laser power-13.04*Welding speed-0.06*Focal distance.
The formation of microstructures and the changes in widths of the fusion zone and heat affected zones have more effect on the developing of mechanical properties of the joints.
Che, Improving mechanical properties of dissimilar material friction welds, Appl.
Sivaprasad, Evaluation of microstructures and mechanical properties of dissimilar materials by friction welding, Procedia.

The principles of the geometrical base parameter are dependent on several factors, such as the bending angle, bending radius, material thickness, bend allowance, bending types and mechanical properties of materials.
In this study, the bending process would be investigated to study the effect of the material mechanical properties and bending geometries, such as a ratio of bending radius to sheet thickness on the bending quality.
The effect of the ratio of the bending radius to sheet thickness ratio and mechanical property were also discussed.
There are many parameters that could affect the K-factor.
The sheet material was a high strength steel, and its properties were taken from the uniaxial tensile test for determining the flow stress.

Study on Properties of Porous Ecological Concrete for Plant-growing in China LI Zhengqi1, a 1Department of Building Engineering, Tongji University, China alzqtjutmd@hotmail.com Keywords: porous ecological concrete; physical and mechanical properties; alkali features; durability; engineering applications.
Both the properties and influencing factors of its physical and mechanical behavior, alkali feature and durability are analyzed.
Also some other factors affect the concrete strength, including ages, strength of aggregate, producing process, curing condition, and so on.
Because of its porous structure, both the inner and outer surface have large area contacting with air and water, so it is more likely to be affected by environment factors, and its durability is critical for its engineering application.
“Research on proportion design and mechanical properties of porous concrete,” Guangdong Water Resources and Hydropower, vol. 1,pp.54-55,59, February 2008 (in chinese)

The Effect of Various Nanoclay Surface Modifications on the Thermal and Mechanical Properties of Amorphous Polyamide Nanocomposites Khairul Anwar ABDUL HALIM1,a*, James E.
This is due to the affinity between polymer matrix and nanoclay is of important factors should be considered.
The type of clay grades significantly affects the mechanical properties of the amorphous polyamide nanocomposites.
In order to achieve a good dispersion, preferably exfoliation of nanoclay platelets, the affinity between polymer matrix and nanoclay is one of the important factors should be considered.
Fig. 3: The effect of different nanoclay grades on the ultimate tensile stress and strain at break for aPA TR90 and aPA TR 90 nanocomposites The type of clay grades significantly affects the mechanical properties of the amorphous polyamide.

Mechanical Properties of Cubic SiC, GaN and AlN Thin Films Jörg Pezoldt1,a, Rolf Grieseler2,b, Thorsten Schupp3,c, Donat J.
The mechanical properties of the epitaxial layers were investigated by nanoindentation.
Compared to non-piezoelectric materials, the piezoelectricity adds an additional energy dissipation path which might affect the vibrational properties and the quality factor of the MEMS device [3].
The mechanical and dissipative properties are affected by the epitaxial layer quality, their dislocation densities and the residual stress.
The mechanical properties of 3C-SiC are mainly studied on thick epitaxial layers, but advanced applications [4] require thin films exhibiting different mechanical properties [2].

China a durisheng851018@163.com , bjhpeng@scut.edu.cn Keywords: TiN/TiAlN coating, Current density, SKH51 steel, Microstructure, Mechanical properties Abstract.
During deposition, the effect of target current on microstructure and mechanical properties is responsible for the number, energy of emission target particles and distribution of target droplets.
In this paper, Ti-Al-N coating on SKH51 was deposited by multi-arc ion plating and the effect of target current (density) on coating's mechanical properties and surface morphology was investigated.
In this study, the adhesion force is controlled by above two factors at the same time.
In order to get a optimal TiAlN coating on SKH51 steel, it is necessary to make further study on the effect of other factors.