Papers by Author: Yuan Tian

Abstract: In this paper, the modified phenolic resin-based adhesive was prepared by dissolving different components. After low temperature curing, SiC samples were bonded by the binder. The samples were treated at different temperatures (400°C, 800°C, 1200°C, 1500°C) under an inert atmosphere. The bonding strength of samples was tested after heat treatment at room temperature. The results showed that the bonding strength of the B₄C modified phenolic resin (PF) based adhesive is the highest. When the heat treatment temperature was above 1200°C, the bond strength increased with the additive amount of boron carbide at room temperature. The microstructures of the samples were observed by optical microscope and scanning electron microscope. The effects of the modified filler and heat treatment temperature on the bonding strength of the phenolic resin based adhesive were investigated. The bonding strength of boron carbide-modified phenolic resin-based binder was tested under high temperature. It was found that the bond strength at high temperature was lower than that at room temperature, and the bond strength decreased with the increase of temperature.

Abstract: Simulation analysis of thermal performance for vacuum glazing was conducted in this paper. The heat conduction through the support pillars and edge seal and the radiation between two glass sheets were considered. The heat conductance of residual gas in vacuum gap was ignored for a low pressure of less than 0.1Pa. Two pieces of vacuum glazing with sizes of 0.3 × 0.3 m and 1.0 × 1.0 m were simulated. In order to check the accuracy of simulations with specified mesh number, the thermal performance of a small central area (4mm×4mm) with a single pillar in the center was simulated using a graded mesh of 41×41×5 nodes. The heat transfer coefficients of this unit obtained from simulation and analytic prediction were 2.194Wm^-2K^-1 and 2.257Wm^-2K^-1 respectively, with a deviation of 2.79%. The three dimensional (3D) isotherms and two dimensional (2D) isotherms on the cold and hot surfaces of the specimens were also presented. For a validity of simulated results, a guarded hot box calorimeter was used to determine the experimental thermal performance of 1.0m×1.0m vacuum glazing. The overall heat transfer coefficients obtained from experiment and simulation were 2.55Wm^-2K-1 and 2.47Wm^-2K^-1 respectively, with a deviation of 3.14%.

Abstract: Laminated glass and photovoltaic laminated glass are widely used in architecture. The interfacial bonding strengths between poly(vinyl butyral) (PVB) and glass were investigated by the cross-bonding method from room temperature to -50 °C. The loading speed was 5 mm/min, and the cooling speed was about 0.5 °C/min. The testing sample was hold at each temperature for half an hour. It was revealed that the testing temperature had great effect on the bonding strength. At room temperature, the tensile bonding strength was 11.49 MPa and the shear bonding strength was 6.61 MPa. With the temperature decreased from RT to -50 °C, the tensile bonding strength was decreased by 66.81%, but the shear bonding strength was increased by 212.16%. From RT to -30 °C, the change rates of the tensile and shear bonding strength bonding strength were 65.57% and 172.68% respectively, only 3.61% and 14.48% from -30 °C to -50 °C. The mechanism for the bonding strength depended on testing temperatures from RT to -50 °C was also discussed.

Abstract: Spherical impact indentation tests with different impact angles (90°, 60°, 45°, and 30°) was carried out to understand the effect of impact angles on damage degree of cement clinker. A linear rail which can adjust angle to alter impact velocity was used to guide the slipping impact head to impact the sample. The different steel wedge was used to change the impact angle. It is found that the area of damage surface for cement clinker is most serious the peak impact force for surface damage decreases but the contact indentation becomes longer with decreasing impact angle when the impact angle is 45°. Under almost the same impact velocity, the smaller the impact angle, the higher the impulse, the longer contact time, and the peak impact force of 45° is maximum.