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Because the local weld of the metal is affected by high temperature in the welding process, every temperature is always uneven after the completion of welding. so in the cooling process, the temperatures of the different dots cause different contractions .This situation will lead to internal forces.
But the welding residual stresses are one of the factors of welding crack formation, they will affect the metal components of the stress and the use, so the detection of welding residual stresses is particularly important.
Because Hauck can eliminate the stress treatment can also improve the influence factors, several fatigue properties of weld areas such as: the residual stress, micro cracks and defects, geometry and the surface hardening, so it is one of the most effective methods to improve the fatigue properties of weld, effect and multiplier It is more suitable for site welding to the large-scale structure, the super higher and lower welding seam and for relieving the weld stress in repairing.
Secondly, the stability of the pressure welding is affected. when the external pressure should be the sum of the yield stress and residual stress compressive stress, the effective area will weaken the components, reduce the stability of compressed weldment.
Because the generating and receiving ultrasonic do not need the coupling agents, and because the laser scanning speeds much faster than the method of mechanical type, so we can achieve rapid scanning imaging with laser ultrasonic system easily.

The wide range between the solidus and liquidus makes the shrinkage porosity prone to happen during solidification, thus affecting the casting quality seriously.
Besides, it can also help to analyse the relationship between the factors and indicators, find how the factors influence the indicators, find the main factor and secondary factor, and find the optimized combination of all the factors investigated.
During casting Process, many factors have impact on the generation of Shrinkage porosity, orthogonal L 9 (3 4)t was selected in this paper ， Three different factors were discussed, casting temperature, mold temperature and mold preheating heat transfer coefficient with the surrounding environment, three values for each factor were selected for simulation..
Fig. 1 Perspective pictures of shrinkage porosity in the zinc alloy ingots Conclusion It could be concluded From the intuitive factor table: the range of the transfer coefficient was maximum, preheating temperature was the second, followed by casting temperature, and the range of heat transfer coefficient is much larger than the value of the other two factors, suggesting that In this study, the heat transfer coefficient was the main influencing factor for shrinkage of zinc-aluminum alloy ingot, their important order was: heat transfer coefficient, pouring temperature and mold preheating temperature.
Engineering Properties of Zinc Alloys.

The main factors are suggested, which influence the effects of the insulating joint, being base on the mechanical analysis of using computer software, and the ranges of concentrated stress are pointed out.
The parameters of the integral insulating joints discussed in this paper are shown in Table 1. 2.2 The function and structure of the integral insulating joints 1- Active end of steel pipe; 2- Locking wire loop; 3-Insulation filler; 4- Steel sleeve; 5- Fixed end steel; 6-Insulation seals Fig.1 Cross-section of integral insulating joint The insulating joint has the same sealing performance, strength properties and insulation performance requirements as buried steel pipeline pipe joints.
The pipeline will certainly suffer multiple stress effect in its running process, but does not affect to separate them for analysis.
According to the properties of material, the material strength that may lead to damage is analyzed.
Because the material at the threaded connection is plastic, not only the tensile stress but also tensional shear stress could have affected on threaded connection

The optimality of composition of zeolite concrete building envelopes can be judged from many points of view, e. g., service life, mechanical properties, or salt resistance.
Material properties [5] of analyzed concretes are summarized in Table 1.
Computational Results and Discussion Service life of building materials is affected by many factors.
The differences were caused by the type of concrete and its hygric properties in particular.
Tsimas, Influence of quicklime addition on the mechanical properties and hydration degree of blended cements containing different fly ashes, Construction and Building Materials 22 (2008) 1191-1200

In the multibody dynamics analysis for motor vehicle, engine excitation, as a major excitation affecting the dynamic behavior of motorcycle frame, should be discussed.
Introduction Dynamics analysis for complex mechanical system in research and development process has been an important technique, especially for the systems with higher speed and less weight, and the study on the major performance of vehicle, including dynamical property, safety, durability and fuel consumption economy, should not be performed only with simplified model or single DOF model.
Although many manufacturers of vehicle and spacecraft have applied CAE technique to perform their dynamic analysis for mechanical system, seldom literatures are still released to discuss about the dynamics of multibody system of complex mechanical products.
In Lagrangian equation with Lagrange multiplier, the rigid body is presented by generalized coordinate of Cartesian coordinate and Euler angles expressed in qi=[x,y,z,Ψ,θ,ϕ]iT, as multibody system consists of n bodies presented as qi=[q1T,q2T,⋯,qnT], the kinematical equation of motion for mechanical system is second-order differential algebraic equation by Eq. 1: (1) ddt[∂T∂q]T-∂T∂qT+λϕqT+μθqT=Q Where: T is kinetic energy; q is generalized coordinate matrix; Q is generalized force matrix; λ is holonomic constraints Lagrange multiplier factor matrix; μ is non-holonomic constraints Lagrange multiplier factor matrix; ϕq,t=0 is holonomic constraint equation; θq,q,t=0is non-holonomic constraint equation.
Summary Definitely, computational simulation on multibody dynamics analysis for complex mechanical system has been a necessary approach in research and development process.

In the case does not affect the construction, these parameters are not easily measured through the on-site test methods, it is also impossible to get through laboratory test methods.
Get the scope of rock mechanical parameters through laboratory test or on-site test, use orthogonal design experimentation[5] to get the complete input data, calculate in FLAC3D to get the output data, factors of each column on each level appears the same times in the orthogonal table, avoid all obstacles as possible, it ensure the neat comparability.
The release of tunnel rock displacement is affected by many factors, take a comprehensive analysis on these factors is important for solving the release rate of tunnel rock stress by establishing calculate model, the major factors which affect the release rate are: the rock quality, the original stress, the project factors, time, and space.[6] In order to simplify the calculation, select the following parameters as input parameters establishment of sample space with FLAC3D: horizontal pressure coefficient , deformation-modulus , friction , cohesion , release rate of stress , where the contains two data and .
All of these factors divide to 5 levels with orthogonal table L25(56).
In order to test the prediction accuracy of network, we construct test samples with uniform design method (choose uniform table U10(108), select 5 properties according to the user guide of the table), then calculate the expected output with FLAC3D model, get the predicted output by the network, and compared it with the expected output.

The experimental results show the microballoons size doesn’t influent the mechanical properties of the syntactic foam significantly.
Syntactic foams are quite different from the conventional foams for they have a close cell structure, which can gain better mechanical performance and controllable property [7-8].
The volume percentage of the microballoons in the syntactic foams had been proved to be an important factor to the mechanical properties of the syntactic foams [9].It is observed that, the density and strength of the syntactic foams decreases with an increasing volume fraction of the microballoons.
Kishore, Ravi Shankar et al investigated the effect microballoons’ size distribution on the mechanical properties of syntactic foams [12], and they found that compressive strength of syntactic foams which having microballoons with narrower size distribution and smaller size is higher.
Because of the different properties of the epoxy resin and glass, the deformation of the matrix and glass microballoons is differed.

Among the factors ruling the superplastic response, chemical nature to the boundaries is reported repeatedly to be a key one.
In effect, yttrium segregation to the boundaries is known to affect the mechanical behaviour [3], mostly playing a negative role [4].
Experimental procedure Sintering procedure and mechanical characterization.
Results Mechanical results.
Thermodynamic properties of 65 elements - Their oxides, halides, carbides, and nitrides.

Introduction Reinforced concrete is the main storage material for natural gas due to its excellent durability and mechanical properties, but the performance research and optimization of storage equipment still face difficulties, and it has certain practical significance for the research on the reliability of its deflection control under ultra-low temperature.
Domestic scholars have made the following research on the deflection control of reinforced concrete: For the flexural members, the main factors affecting the reliability of the member’s deflection control in descending order are the relative values ​​of variable action effects ρQk, the relative cross-sectional area of compression flange γ`f and the reinforcement ratio of longitudinal tensile steel bars ρ[1]; the performance of reinforced concrete beams shows that as the temperature decreases, the brittleness of the reinforced concrete beams increases, and the stiffness has certain fluctuations[2].
The reliability indexes of the bending beam under various temperature gradients under various variable factors are shown in Table2, compare the changes of various factors under various temperature gradients of ultra-low temperature, and obtain the influence of various factors on the reliability index under various temperature gradients.
(2) Compare the changes of various factors under various temperature gradients, and calculate the difference of the extreme value of the reliability index β.
Experimental study on the mechanical properties of concrete under low-temperature-normal temperature cycles.

Comparative investigation of optical properties in Tm3+/Er3+/Yb3+ co-doped oxyfluoride tellurite and germanate glasses Yuebo Hu1,a, Jianbei Qiu2,b, Dali Zhou3,c, Dacheng Zhou2,d, Rongfei Wang2,e, Qing Jiao2,f, Zhiguo Song2,g, Zhengwen Yang2,h 1 Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500, China 2 Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China 3 College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China ahuyb@kmust.edu.cn, bqiu@kmust.edu.cn, czdl@scu.edu.cn, dzhoudacheng123@163.com, ewang-rong-fei@163.com, fjqyxt@yahoo.com.cn, gsongzg@kmust.edu.cn, hyangzw@kmust.edu.cn, Keywords: Up-conversion luminescence; Tm3+/Er3+/Yb3+ co-doped; Oxyfluoride Glass; Optical properties; Phonon density Abstract.
However, it is difficult to fabricate fluoride glass fibers owing to their low chemical and mechanical stabilities.
In this paper, we comparatively investigated the optical properties of Tm3+/Er3+/Yb3+ co-doped oxyfluoride tellurite and germanate glasses under 980 nm excitation at room temperature.
Therefore, we believe that there must be other important factors that affect the UC efficiency.
In this present work, the dependence of emission properties of TYET and GYET glasses on different excitation power was also investigated, and the results are depicted in log-log plots of as shown in Fig.4.