Sensitivity analysis and probability modelling of the structural response of a single-layer reticulated dome subjected to an external blast loading

Abstract

The structural response of a single-layer reticulated dome to external explosions is shaped by many variables, and the associated uncertainties imply non-deterministic results. Existing deterministic methods for predicting the consequences of specific explosions do not account for these uncertainties. Therefore, the impact of the uncertainties associated with these input variables on the structures’ response needs to be studied and quantified. In this study, a parametric uncertainty analysis was conducted first. Then, local and global sensitivity analyses were carried out to identify the drivers of the structural dynamic response. A probabilistic structural response model was established based on sensitive variables and a reasonable sample size. Furthermore, some deterministic empirical methods for explosion-resistance design, including the plane blast load model of CONWEP, the curved blast load model under the 50% assurance level, and the 20% mass-increased method, were used for evaluating their reliability. The results of the analyses revealed that the structural response of a single-layer reticulated dome to an external blast loading is lognormally distributed. Evidently, the MB0.5 method based on the curved reflector load model yielded results with a relatively stable assurance rate and reliability, but CONWEP did not; thus, the 1.2MB0.5 method can be used for making high-confidence simple predictions. In addition, the results indicated that the structural response is very sensitive to the explosion parameters. Based on these results, it is suggested that for explosion proofing, setting up a defensive barrier is more effective than structural strengthening.

Keywords

• Dome structure
• Blast load uncertainty
• Sensitivity analysis
• Probabilistic investigation
• Reliability evaluation