为满足建筑用安全型真空玻璃构件的开发及工程应用推广之需要,研究了真空玻璃结构优化设计所涉及的力学基础理论。根据真空玻璃构件结构特点,建立力学模型,分析了真空玻璃构件在大气压作用下支撑应力分布特征及计算公式。结果表明:大气压作用下真空玻璃构件最大弯曲拉应力分布在支撑部位玻璃外表面处,当支撑力超过其临界载荷时,会导致接触点附近玻璃锥形裂纹的产生;根据均强度理论,得到了玻璃基片在不产生压痕下支撑物的最大临界支撑力计算公式;给出了持久应力作用下真空玻璃基片的强度设计值,其中钢化玻璃的为44.40MPa,普通浮法玻璃的为8.19MPa。综合真空玻璃构件应力分布特征及传热机理,优化了真空玻璃构件设计,使其达到最佳"热学与力学"配置。
In order to develop a safe vacuum glazing,the strength theories for the optimization design of vacuum glazing was investigated.The mechanical models were proposed and the stresses in the vacuum glazing due to atmospheric pressure were calculated according to the structural characteristics of the vacuum glazing.The critical support force in the pillar was determined based on the mean-stress criterion.The design strength of the glass under long-term stress was analyzed.The calculated and experimental results show that the maximum tensile stresses are distributed on the external surface of the glass sheets in each support pillar.A conical crack might be formed if the support force of the pillars is higher than the critical force.The design strength of the glass at the long-term stress for tempered glass is 44.40 MPa,and that for float glass is 8.19 MPa.Considering the combined mechanical and thermal properties,the design for the vacuum glazing was optimized.