Search results

The caused variant selection can significantly affect the mechanical performance of the superalloy.
However, the effects of DSA on the thermal mechanical responses of IN718 disc during the quenching process are rarely investigated and unclear.
The present modelling prediction of residual stress depends on both heat conduction simulation and the used mechanical model.
On the other hand, the accuracy of the contour method also depends on many factors, e.g., the cutting process, the measurement technology of the contour, etc.
Barsoum, Influence of thermo-mechanical material properties of different steel grades on welding residual stresses and angular distortion, Materials & Design (1980-2015) 65 (2015) 878-889

A wide range of consolidated methodologies [1-3] is available for single-value property optimization (i.e. hardness, elastic modulus, yield strength).
However, when looking at the fatigue resistance, the optimization problem grows in complexity as the fatigue limit does not give an overall picture of the global behaviour and the number of cycles to failure is strongly influenced by other factors.
Parameter optimization is an important topic in almost all sciences and many suggestion and methodologies can be derived from disciplines far from the field of mechanical and materials engineering.
Such limitation affects the result accuracy and often leads to a partial understanding of the treatment under investigation.
By using the estimated weighting factors it was possible to calculate t and T values that maximize the fatigue life at given amplitude stress.

Numerous factors are implicated in the corrosion processes and can act in concert.
This reveals a complex effect of this parameter, as indicated by the numerous (beneficial or detrimental) actions mentioned in the literature: (i) increased oxygen activity in the simulated H2Ocontaining atmosphere, (ii) accelerated oxidation due to the fact that the size and charge of the OH ion are lower than the ones of the O 2 ion [8], (iii) increased scale porosity in the presence of H2O favouring oxygen diffusion [9], (iv) modified scale mechanical properties [10, 11], (v) enhanced volatilisation of Cr-compounds [12], (vi) modified acido-basicity of the molten compounds involved in a fluxing action [13, 14], and (vii) reduced Cl2 partial pressure due to the displacement of the Deacon reaction (Eq. 4) [13].
The nature of the chloride did not appear to affect the scale formation.
It could however be attributed to better mechanical properties in presence of H2O, reduced Cl2 partial pressure, and modified acido-basicity of the molten phases.
The conclusions obtained concerning these complex systems, where numerous factors act singly or in concert, are as follows: (1) In coal-fired plant superheater environments, the participation of molten alkali-iron trisulphates in the corrosion mechanism was confirmed: actually the degradation depended on the alkali sulphates and SO2 contents, and on the temperature.

The signal drift of this sensor affects the measured angle and is mainly caused by the change in enviromental temperature.
It was proved that the error would increase 30 nm due to the thermal deformation of the system’s mechanical structure if the environment temperature varied 1 °C [4,5].
The material properties of the U-shaped holders are listed in Table 1.
It has been proved that the thermal deformation of the mechanical structure for a high precision angle sensor is the key factor of the sensor’s drift [16].
Fei, et al, Theory and application of mechanical thermal deformation, National Defence Industry Press, 2009

Ren School of Mechanical Engineering, Shandong University, Jinan, 250061, China Keywords: Theoretical model, Diamond wheel, Hard and brittle materials, Drilling Abstract.
Introduction As a kind of typical hard and brittle material, engineering ceramics are differentiated from traditional ceramics by the specialized properties they process, high hardness, high thermal resistance, chemical steadiness, and low thermal or electrical conductivity and so on.
The property profile of these materials allows an economic production of structural parts only by finishing with diamond tools or special machining technologies.
A critical load Pc for the initiation of a median crack is given by [7]: H K P 3 V 4 IC c ��= . (1) where, � is a dimensionless factor related to the indenter geometry; KIC is the fracture toughness of workpiece material; HV is the Vickers hardness of workpiece material.
As there are some other factors affecting Mv, for example the flushing of swarf and self-sharpening of abrasive grains, the Mv is not proportional to the rotation speed of the drilling tool.

However, there are still many factors have influences on the vertical earth pressure of high embankment culvert and load reduction efficiency, including the number of geogrid layers, stiffness of the geogrid reinforcement, the geometry of the load reduction ditch, etc..
Numerical analysis The selectio of the analysis model, including geometric model and material model, will directly affect the accuracy of simulation.
In this paper, physical and mechanical parameters used were listed in Table 1, and the axial tensile stiffness of geogrid EA is 1200kN/m.
Table 1 Physical and mechanical parameters for numerical simulation Material Elastic modulus(MPa) Unit weight(kN/m3) Poisson’s ratio Cohesion(kPa) Friction angle (°) Culvert 30 000 25.2 0.20 － － Silty clay 7.8 17.8 0.33 7.6 19.7 Sand and gravel layers 30 20.1 0.3 0 28.6 Clay 24.1 18.3 0.3 15.7 21 Fill 18 19 0.3 16.8 24.6 Compressible material 2 14.8 0.36 0 28 *The material properties were obtained from the laboratory test.

The material is SS316L with mechanical properties: σs=268MPa, E=210GPa, u=0.3, K=1632, n=0.61.
Actually, springback may be also affected by many factors, which needs further detailed investigations.
Vol.209 (2009), p. 3431 [5] M Bakhshi-Jooybari, M Elyasi and A Gorji, in: Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2010 224: 95 DOI: 10.1243/09544054JEM1586

Introduction With the development of near-surface materials science a basically now method of modification of structure and properties of crystals, ceramics and films appeared.
Ordered quantum well structures also occur at low-angular twist boundaries and packing defects [1–3]; besides, proton modification, interaction modulation of H–M and H–H [2, 4], isotope ordering [5, 6] and other factors promote to their formation.
The growth of material strength properties [7, 8], realization of nonlinear optical affects [9, 10] and two-dimensional holographic recording of information [11] have been achieved.
At the same time there is a real possibility of considering physical laws and laws of conservation in elliptical sрасe on Clifford surface in the same way as on Euclidean surface due to the unique properties of Clifford surface.
All of them can serve as an instrument for studying geometric properties of systems with disordered centres and their local environment.

One of the most useful properties of metals is that they can be easily shaped or bent and have the advantage of reverting back to their original size.
Crack propagation in this region is difficult to predict since it depends on the microstructure and flow properties of the material.
The term Cp is the retardation factor to reduce the growth rate.
One of the most useful properties of composites is the ability to produce a part that has strength in the direction required and thus minimising component mass by reducing material in directions that does not play a role in handling loading.
For example, composite materials are affected by environmental conditions hence the Time-Temperature Superposition Principle (TTSP) is a concept used when there is a strong dependence of viscoelastic properties on the temperature at which they are measured [5].

Various factors that may be potentially responsible for the strength enhancement of metallic foam are discussed as well as testing methods using large diameter Nylon pressure bars in SHPB set-up and experimental results are presented in Section 2.
As the attenuation coefficient is also affected by the geometric effect, it has been proved [14] that such an approach gives wrong results.
International Journal of Mechanical Science 30 (3-4), 273292
International Journal of Mechanical Science 26 (11-12), 689-701
An investigation of the mechanical properties of materials at very high rates of loading.