Evaluation of Core Tensile Strength Using the Weibull Distribution

The purpose of the experiment was to assess the Weibull distribution analysis technique in determining core properties of silica sand core strength test cores using the phenolic urethane cold box process. Nine engineered sands designed around a constant grain fineness number were used to demonstrate the variability of sand distribution on core tensile properties. A normal distribution analysis was performed and compared to the Weibull distribution analysis. Using average core properties and standard deviations as a performance criterion in ranking the nine different engineered sands, the normal distribution could not fully distinguish reliability. When the Weibull distribution analysis was performed, core strength reliability was clearly demonstrated. Additionally, the core position in producing the test samples was shown to be a function of sand distribution. The Weibull distribution analysis clearly showed its statistical versatility when skewed sand distribution was included in the performance analysis.