Wei Hong Li

Thermal Stress Analysis of Photovoltaic Hollow Glass Based on ANSYS

This article through to hollow photovoltaic glass service in the process of temperature test, by using the finite element simulation of the temperature change caused by the thermal stress, using the finite element simulation of the temperature change caused by the thermal stress. According to the heat conduction equation and boundary condition, derivation hollow photovoltaic through the finite element software to hollow photovoltaic glass plate thermal stress for numerical simulation and research. Adopted in structural analysis directly define temperature load method analysis force hollow photovoltaic glass thermal stress. Use the finite element software to hollow photovoltaic glass plate thermal stress for numerical simulation and research. For the known temperature field distribution situation, adopted in structural analysis directly define temperature load method analysis force hollow photovoltaic glass thermal stress. Through the finite element software ANSYS to calculate different unit was carried out and the numerical simulation, the results show that the analytical solution and the numerical solution has good goodness of fit. The proposed calculation formula for engineering design has the certain reference value.

Influence of Stress Parallel to Crack Plan on Subcritical Crack Propagation in Glass under Biaxial Stress

The aim of this study is to demonstrate the influence of the stress parallel to the crack plane on subcritical crack growth in brittle materials by using a numerical code MFPA2D. The mechanism of this influence is also discussed. The curves of subcritical crack extension vs. strain of brittle materials under uniaxial and biaxial stress were obtained through numerical tests with acoustic emission consideration. The results showed that the tensile stress parallel to the crack plane has the effect on crack arrest, while the compressive stress parallel to the crack plane plays important role in crack opening process. The numerical results were consistent with experimental observed result, which shows the reliability of the numerical method, and provides theoretic foundation for failure analysis and life estimation of brittle materials.

Chloride Ion Erosion in Concrete under Sustained Axial Pressure

As one of the leading causes of influencing the durability of concrete structure, reinforcement corrosion has been a central issue. Erosion of chloride ions on the concrete structure is influenced by many factors. This is not only concerned with its own structural properties, but also to its environment, to withstand the load and other factors. This article has carried on an experiment which researches on the rules of chloride ion penetration in the sustained axial compression after different corrosive time, when the concrete is corroded under the joint action of axial compression load and chlorine salt circulation. The results prove that, with the increase of Intensity of load and the cycle time of chlorine salt, the number of Chloride ion ingress in concrete continues to increase. The experimental results may provide a reference to the durability design of concrete in chloride environment.

A New Method for Studying the Damage in Concrete Subjected Single Face Salt Freezing Cycle

Aiming at the shortcomings of traditional research method of materials mechanics performance of concrete, this paper presents a new method to test the mechanical properties of concrete material layer body--the relative method. It focuses on the use of relative principle, testing dynamic elastic modulus of concrete damage layer subjected to single salt freezing cyclic, and draw a gradient damage curve of concrete, and then study the damage process of the concrete under the effect of salt solution and the freeze-thaw cycle synergetic factors. The method provides a new way to test body layer mechanical performance of concrete material which the traditional methods can not be directly solved.

Penetration of Chlorine Ion in Concrete under the Coupling Effect of the Continues Pressure Load and the Corrosion Environment

This paper studies the influence law of experiment time, load level under sustained pressure load and the corrosion environment interaction on the permeability of chloride ion in concrete,which is through natural diffusion method. Experimental results show that with the increase of the test time, the penetration depth of chloride ions in concrete and the content of chloride ions in the same penetration depth is growing. As the load level increases, there is a tendency of the chloride ion content after the first increase and then decrease, the turning point in the middle remains to be studied. The research results have a certain significance for concrete durability design and life prediction in corrosion environment.

Design and Application of a Test Device for Concrete Durability under the Action of Multiple Factor Coupling

This paper discusses the testing equipment of concrete deterioration under the coupled action of multiple factors. It discusses the classification, advantages and disadvantages which are related to the test system and studies the charge loading device design and the key problems. At last the paper forecasts the prospect of loading device design.

The Brief Analysis of Photovoltaic Insulating Glass in the Process Service

This article according to intensity of solar radiation in Beijing region during summer based on this intensity of solar radiation the working temperature of photovoltaic insulating glass were measured. On this basis, the atmospheric pressure which in hollow layer of photovoltaic insulating glass were measured. And the stress of glass is calculated by finite elements software. The results showed that if the glass deflection is less 1 proportion of glass thickness there is a linear relation between stress and deflection. This is a small deflection issue. If the proportion exceeded this limit, the stress exhibited a non-linear relationship with deflection. This is a large deflection issue. The glass stress and deflection ratio which calculated by finite elements is less than the criterion which prescribed by Glass curtain wall project technical specification. The results show that the formula which introduced reduction coefficient used in standard is favors of the security.

The Durability and Damage Testing of High Performance Concrete

Concrete structures are widely used in engineering structure, but because of the problem of environment and material, the durability of the concrete structure appears. This paper first states the main research content of the durability of concrete structures, then introduces the main ways to improve the durability of concrete structure. Finally it summarizes several kinds of concrete damage testing technology and characteristics, and the construction engineering testing technology is prospected.

The Analysis of the Function and Principle on Air Cooling PV Double-Glass Window

This article presents a new kind of photovoltaic window - Air-cooling PV double-glass window. The structure and principle of air-cooling PV double-glass window is introduced. The study pointed out that photoelectric transformation efficiency of photovoltaic cells hpv is an important parameter to evaluate the electric performance of PV systems, and also gives a expectation on future work.

The Influence of Stress Ratio on the Fracture Behavior of Brittle Materials

The fracture behavior of brittle materials under different stress ratio has been investigated by means of numerical simulation method with software RFPA2D (Realistic Failure Process Analysis). The fracture dependence of brittle material on biaxial plane stress state was confirmed. The results show that the critical stress intensity factor under biaxial stress increases with the increase of biaxial stress ratio. The simulation tests reveal that the biaxial stresses have strong influence on the fracture properties of glass. The results confirmed that the strain criterion of fracture is feasible while brittle materials under complex stress state.