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Study on CTOD Fracture Toughness of Welded Joint of X80 Marine Drilling Riser Peng Wang1, a, Meijuan Hu1,b and En Dang2,c 1Key Laboratory for Mechanical & Environment Behavior of Tubular Goods, CNPC Tubular Goods Research Institute, Xi’an, Shaanxi, 710065, China 2Bao Ji Oilfield Machinery Co.
The three point bending specimens are made in the weld center line and heat affected zone for the butt-welded joint in Φ533×25.4mm X80 marine drilling riser respectively according to the requirement of the standard.
Thus, it is very necessary for marine drilling riser to evaluate the fracture toughness property of the welded joint.
CTOD (crack tip opening displacement) is an important parameter to assess the property of anti brittle failure for base metal and welded joint, which could be used to evaluate the safe reliability of structure [3].
Testing Method According to BS 7448 Standard, three point bending experiment is performed at 0℃, in which the displacement is controlled monotonic loading at a constant rate of increase in stress intensity factor within the range 0.5 to 3.0 during the initial elastic deformation.

Table 1 presents the material properties of PZT-4, Tungsten and Steel [26].
,Ne; j = Np + m with the properties of elastic materials.
For the media Ωj = Ωem with pure elastic properties, only stress fields would be considered.
The modeled material properties are listed in Table 1.
For PEHs, the most important factor affecting the efficiency with which mechanical energy is converted to electrical energy is its resonant frequency.

The deformation caused by cutting force is the main factor that decides wheel groove broaching deformation.
Although it has the advantages of high temperature resistant, then the poor performance in the mechanical machining is obvious.
(1) Where: Fz—Cutting force per unit length on the cutting edge (N/mm); ∑b—The total cutting width (mm); Z—The number of work teeth at the same time; K1, K2, K3—The correction factor of cutting force, represent the correction factor of anterior horn, the cooling lubricant and tooth wear degree affect.
Turbine disk’s material is high temperature alloy GH4698, and the material properties are given to the model.

Tissue extrinsic factors will clot the blood while the bleeding vessels will be thrombosed by platelets and intrinsic factors. 2.
In 1989 (Howlett et al.) using interconnected (on average approximately 100 microns) porous silicon nitride ceramics we demonstrated several key factors [1].
At this stage, it seemed to me that a more commercial and productive avenue to influence tissue along the bone /prosthetic material interface was to change the surface chemistry leaving the bulk properties as is and thus manipulate cells and their differentiation.
Of the gaseous ions used, only oxygen had a short-term cellular adhesive affect [2].
A (2002) "The role of growth factors in the repair of bone: Biology and clinical applications" The Journal of Bone and Joint Surgery Vol. 84A: 1032 - 1044. 14.

In recent years, a great deal of research have been done [2]~[5].However, the most studies have been on solid piles, and research on the vibration property of pipe pile is relatively rare.
The longitudinal vibration boundary value problem of thin-wall cast-in-situ pipe piles in embedded axisymmetric uniform viscoelastic foundation and dynamic response problem of thin-wall pipe pile on low strain and variable impedance are researched by Xuan ming Ding etc[7], [8].The coupled torsional vibration theory between the saturated heterogeneity soil and pile was studied by Zhi Qing Zhang[9].Because the soil in the lasting load usually show creep characteristics, in order to depict the mechanical behavior of soil, it is necessary to take the soil as a viscoelastic media.
Torsion vibration displacement amplitude of the soil of inside pile is as follows: (14) Where, .From Eq. 14, amplitude of tangential shear stress on unit area affected by the soil of inside pile, ‘’,can be written as: (15) Where, represents the first type of Bessel function for the second order deformation.
of the torsional complex stiffness of the pile top, (30) In order to convinient for calculation, the dimensionless factor of the torsional complex stiffness of the pile top is written as: ,is the real stiffness of the pile top, is the Dynamic damping of the pile top。
Conclusion Through parameter analysis, the factors influencing the torsional dynamic impedance of the viscoelastic soil are discussed.

Main auxiliary variables which affected the dyeing uptake rate including temperature, holding time and pH.
where is the forgetting factor,; is a sufficiently large positive number; is the correct power factor; is the positive covariance matrix.
According to the equivalence property between GPC and DMC control law, the predictive vector is shown as (8):
Considering the robustness of the control system and how the present control output affects the future time of the system, we define the performance index as (9):
The predictive length n=6; the length of time domain p=6; the length of control m=2; control weighting coefficient; forgetting factor;;.

Erosion and corrosion predominantly affect the efficiency and life of machinery used in the chemical and mining industries [4].
Improving operational properties and wear resistance of essential machine parts is acute for modern machine engineering.
Among the works devoted to technological methods of improving operational properties the ones aimed at improving stability of cutting processes, materials and coatings should be mentioned at steel [7-9].
Owing to the combination of good mechanical properties and excellent corrosion resistance, steel is widely used in mining machinery [10, 11].
Among the commercially available alloys, steels are well-established candidates for applications where good mechanical properties and high corrosion resistance are demanded.

The results indicate that the micro-crystalline alumina SG abrasive wheel with large specific volume has good grinding properties when grinding Inconel 718 in comparison of the wheels with PA abrasives or SG abrasives of small specific pore volume.
Some important factors, such as the grinding forces and temperature, were investigated, and surface roughness was used to describe the surface quality.
It was strengthened by depositing and deformed at high temperature, which has high strength, high fatigue property, and fine plasticity at the temperature ranging from -325 to 650℃.
The grinding force can affect wheel life, surface roughness and specific energy, which is often regarded as an assessment parameter in grinding process, because it is convenient to be obtained and controled.
Grains of SG abrasive characterize perfect abrasiveness owing to the micro-crystalline structure and isotropy of physic-mechanical properties and also the ability of self-ageing proceeding on a micro scale.

The recycled aggregate concrete must, however, satisfy certain mechanical and durability requirements before it can be used as a structural material.
Perhaps, the most important of these factors is the ability of concrete to resist flow of fluids through it: a property that is referred to as permeability.
The resistance to chloride-ion penetration into concrete is a crucial paramete affecting the durability of concrete structures exposed to marine environment [2].
So far a number of studies have been performed by using recycled aggregate in concrete attempting to understand the properties of RAC; Among them, most of the studies are mainly focused on the mechanical properties of the resulting concrete, limited work is carried out on the understanding of the durability aspects of the emerging construction material as is probably with concrete that is made with natural aggregate [3].
Xu: Expwrimental Study on Influence of Recycled Coarse Aggregates Contents on Properties of Recycled Aggregate Concrete.

As such, big safety factor and margin are used to meet the strength requirements.
The material properties are shown in table 1 and the geometry of the model is shown in figure 1.
Table 1 Material properties material Modulus of elasticity E Poisson’s ratio Allowable stress in the design pressure and temperature 09MnNiDR 0.3 163 09MnNiDⅢ 0.3 163 Fig.1 The geometry of the model 1.2 Mesh 1/4 areas of the model is taken because of its symmetry of structure (the geometry and the load is symmetrical).
Some details of the actual structure are ignored, such as welds, transition circle angle and so on, which will not affect stress distribution at the junction, but can greatly reduce the number of units.
[3] Weiwei Yu and Bingjun Gao: Application of ANSYS in mechanical and chemical equipment (China Water Conservancy and Hydropower Press, Beijing 2006), in Chinese