Practical Application of the Concept of Separating the Zone of Overheating and Reducing the Stress Level in Cathode Block of an Aluminium Electrolytic Cell During Formation of Connection with the Steel Pin by Cast Iron Pouring

The article presents the concept of division of a carbon block into single cathode sections to reduce stresses that occur during thermal shock accompanying the operation of pouring cast iron into a shaped groove in which the current-carrying steel pin is mounted. The temperature field and the state of stress were determined by FEM. Experimental measurements were used to determine the core displacement during pouring operation. The calculations were verified by thermovision and photoelastic method. Based on the temperature field and stress field analysis, a method for the block division into sections has been proposed, resulting in a significant reduction of the stress level.

Semiquantitative Test Method for Degradation Ratio of Vacuum Degree of Vacuum Glazing by Photoelastic Method

Vacuum failure will lead to insulation function failure and increasing huge potential security problems for vacuum glazing, it is necessary to inspect the vacuum degree value of the vacuum glazing in service. In this work, the relationship between the bearing behavior and vacuum degree value of the vacuum glazing was studied by experiment, the experiment results show that the bearing behavior of vacuum glazing showed a greater than 50% reduction after the vacuum degree lose completely in vacuum cavity of the vacuum glazing. One test technique for degradation ratio of vacuum degree of vacuum glazing by photoelastic method was developed in this study. Through linear proportional relationship between support stress spot size and degradation ratio of vacuum degree observed via photoelastic method, vacuum degree completely disappear and stress spot size is 0. So, the ratio R(less than or equal to 1) represent the relative differential pressure between the support stress spot size tested in-situ and the support stress spot size measured in vacuum degree intact environment. The degradation ratio of vacuum degree is (1-R) %. Obtaining qualitative or semi-quantitative assessment of vacuum degree degradation ratio of vacuum glazing through observe support stress spot size with photoelastic apparatus.

A Study on Residual Stresses in Machined Brittle Material

Residual stresses in fused silica induced by two machining methods, diamond blade saw cutting and GC grinding wheel grinding, are studied in this study. Photoelastic method would be applied as measuring tool analyzing the gradient of residual stresses caused by different machining condition. This sentence is strange with analyzing the chips of grinding and observation of surface defects, it is assumed that the stresses gradient differs probably cause by the different material removal mechanism.