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It is inconclusive whether dynamic strain ageing has a positive or negative effect on the fracture properties of materials.
Material properties representative of an Al-3Mg 5XXX alloy are taken from Kok et al. [12].
This is done for three reasons: it can be difficult to obtain valid measures of mode II mechanical properties, for the ease of implementation, and because the loading is primarily mode I-the mode II properties should not affect the solution significantly.
These properties result in critical normal ∆nc and shear ∆tc displacements equal to 6.36 x 10−5 m.
American Society of Mechanical Engineers, 1999. 8

During the production of the low-pressure casting aluminum wheel hub, the head face deformation and axial deformation of the casting blank are always happened due to various factors.
The aluminum wheel is commonly produced by the low-pressure die casting (LPDC) technique for smooth filling, heat-treatable property, high dimension accuracy and internal quality of the cast wheel.
However, during the low pressure casting process, the actual shape of the casting wheel would deviate from the theoretical shape due to various factors such as size of the mold, casting pattern, spraying ash thickness, hot deformation of the blank and heat treatment.
If the axial deformation is beyond tolerance, the size of hole will be inaccurate, and that will affect the overall appearance of the wheel.
Traditionally, the measurement of the deformation is usually static and by traditional handwork which can be easily affected by the adjustment of the tools and human experience, and the accuracy and the reliability is limited.

The influence of the addition of spongilites on the physico-mechanical properties, frost-resistance, and microstructure of cement mortars as a function of time was studied.
Fresh state properties of cement-spongilite mortars.
Summary This paper has focused on the effect of two types of spongilites on the fresh state properties, mechanical properties, microstructure, and frost resistance of cement mortars.
Šrámek, Relationships between mineralogy, physical-mechanical properties, and durability of cretaceous calcitic spongilites, in: J.
Rovnaníková, Pozzolanic properties of brick powders and their effect on the properties of modified lime mortars, Constr.

Therefore, it is believed that the fatigue threshold of the UFG metals is profoundly affected by the microstructural stability.
Because the stress intensity factors are calculated based on linear elastic fracture mechanics (LEFM), to satisfy the small scale yielding condition, the specimens should be thicker than 2.5(Kmax/σys)2, where Kmax is the maximum stress intensity factor during cyclic loading and σys is the yield strength [11].
Therefore, it is believed that intergranular FCG is characteristic of UFG structures, and obviously, the grain coarsening profoundly affects the FCG behavior.
Benson, Mechanical properties of nanocrystalline materials, Prog.
Cavaliere, Fatigue properties and crack behavior of ultra-fine and nanocrystalline pure metals, Int.

Tendency of recycling industry Today, under the pressure of environmental legislation, economic and technological reasons are no longer the only factors that drive the automobile manufacturing industry and recycling industry, they are shifting toward sustainable waste management of ELV.
They also studied extrusion and molding technologies in order to make the modified recycled material meet requirements for mechanical properties, moldability, paintability and surface quality, and reduced the number of process steps and processing time.
In their observation, the recycled material showed a strong degradation in the mechanical and impact properties due to the occurrence of thermo-oxidative and thermo-mechanical degradation phenomena taking place during processing and reprocessing.
By this procedure materials with properties suitable to be reused for the same or for similar applications within the car have been obtained. 3.3.
They reached a conclusion that up to 25% foam by weight could be replaced by laminate without affecting adversely compression or fatigue properties, thereby providing a potentially useful route to recycle automotive laminates.

Corrosive media affects the initiation and growth of fatigue cracks[1,2].
The basic mechanical property of the material is listed in Table 1(Details in Ref. [5]).
Table 1 mechanical properties of 30CrMnSiNi2A Elastic modulus (MPa) Possion ratio Yielding stress(MPa) Ultimate stress(MPa) 200000 0.33 1189 1580 The corrosive environment components are following
The interface of the mixed liquor is just located on the crack surface of the test sample so that the cracking surface can be affected together by the two different corrosive liquors.
Table 4 Critical crack sizes under different corrosive environments Corrosive environment Critical crack size(mm) Lab air 19.8 Moist air 20.2 3.5%NaCl 20.2 Oil-box zone 20.4 Dried air 20.1 Tank seeper 19.4 Cookroom&washroom 20.5 High altitude 19.4 Conclusions (1) The corrosive media could accelerate crack growth rate of steel 30CrMnSiNi2A in different degrees, which shows that environment factors are indispensable to damage tolerance design of aircraft and must be considered in crack growth analysis

Effects of Process Parameters on Surface Quality in Turning of Mild Steel with Rotary Cutting Tool Murat Kiyak1,a, Erhan Altan2,b 1 Yildiz Technical University, Department of Mechanical Eng., Besiktas 34349, Istanbul 2 Yildiz Technical University, Department of Mechanical Eng., Besiktas 34349, Istanbul akiyak@yildiz.edu.tr, bealtan@yildiz.edu.tr Keywords: Rotary tools, surface roughness, self propelled rotary tool Abstract.
Introduction During machining, heat generation affecting tool and workpiece is seen.
Ezugwu et al. investigated the general properties of the self-propelled rotation tools, factors effecting tool life, tool wear and surface quality of the machined surface and they compared the results with that of conventional tools [2].
Dessoly: Modeling and Verification of Cutting Tool Temparatures in Rotary Tool Turning of Hardened Steel, Master of Science Thesis in Mechanical Engineering Georgia Institute of Technology (2004) [10] L.

For design engineers the choice of the macro-mechanical level in modeling is mandatory wrt get- ting macro-mechanical stresses from numerical analysis.
Describing failure by macro-mechanical stresses in general is different to an application of the really failure mechanisms-causing micromechanical stresses (see later the IFF1). 2 The Failure Mode Concept (FMC) 2.1 Lamina Stresses, Invariants, and Properties Figure 1 depicts the 3D state of stress, the 5 strengths, and the 5 elasticity quantities of a UD material element.
Determination of the Degrading Elasticity Properties of the Lamina: By employing the equivalent stress reached in each failure mode the associated secant modulus of each mode was determined for the hardening and the softening regime.
It is still too time-consuming and pre-processing does not inform about design driving modes as well as reserve factors, [8], demanded for the 'Proof of Design'.
Composites Science and Technology 58 (1998), 7, pp. 1001-1010 [4] Soden, P.D., Hinton, M.J. and Kaddour, A.S.: Lamina Properties, Lay-up Configurations and loading conditions for a Range of Fibre-reinforced Composite Laminates.

Introduction Grain size refinement is a well known technique to improve mechanical properties of metallic alloys.
These materials exhibit attractive mechanical properties, in particular high mechanical resistance.
Moreover, if the alloy is partially crystallized after forming, its properties in use can also be modified.
The mechanical properties (i.e.
Compression tests confirm also that the mechanical properties of the glass were not significantly modified by the thermoforming process.

So far, not very much has been done in the area of thermal transport properties of FGM`s.
Having these two properties, also heat capacity can be calculated.
It is obvious that these properties do not show a linear relation with composition.
Properties like density and heat capacity are to be seen as dependent solely on the quantity of each component.
For the thermal transport properties TC and TD, the situation is more complex.