Reliability Analysis And Risk Assessment Of Single-layer Reticulated Domes Subjected To External Blast Loading

Recently, various kinds of terrorist attacks occurred frequently in all over theworld. Especially, the―USA Terrorist Attack911‖which shocks the world hasbrought tremendous casualties and economic losses, as well as sounds the alarm ofsecurity against explosion. Car bombs become the first choice for terrorists, due toits flexible and unobtrusive characteristics. Besides, the large-span spatial structures,with important political significance and graceful architectural modeling, are oftenthe target of terrorist attacks. Therefore, it shows extremely important theoreticalsignificance and application value to study the failure probability and riskassessment of large-span spatial structures under external blast loading.ANSYS/LS-DYNA finite element software is applied in this paper to therefinement model for K8single-layer spherical reticulated shell structures. Theeffects of structural responses under external blast loading between ALE (Arbitrary-Lagrange-Euler) algorithm and CONWEP have been summarized. In this paper, theresults of the two methods and the fitting formulas in the reference have beencompared to verify the feasibility of CONWEP to calculate structural responses.Considering the calculation accuracy and computation time, CONWEP blastsoftware is chosen as the final calculation method for external blast loading ofspatial structures.According to the basic principles of structural reliability analysis, suitabledamage states and the corresponding damage factor ranges are determined foranalyzing blast response of reticulated shell structures. In the paper, Monte-CarloAnalysis Method was used to obtain the probability of different damage states andstructural reliability curves of5single-layer reticulated domes under external blastloading. This work provides theoretical support for both risk assessment and repairreconstruction of the large-span spatial structures under external explosive loads,such as the car bomb attacks.According to the basic principles of building structure probability riskassessment, the paper put forward the analysis methods of protective measures ofthe single-layer spherical reticulated shell structures and the calculation model ofstructure economic losses.Using the failure probability of structures, the effect ofprotective measures i.e. bollards to the structural damage states and economiclosses of ingle-layer reticulated domes were analyzed. By investigating therelationship between net benefits of structure protective measures and bollardsstandoff, the most optimal standoff has been worked out. A single-layer sphericalreticulated shell structure was carried out on life investment optimization design.Structure initial cost, maintenance cost and structure economic loss are calculated to get the total investment of three structures, and the optimal structure underexternal blast loading was determined.