1. About

This open-source research application, is released in GitHub (PBE Github page) under a BSD 2-Clause license (see Copyright and License). The PBE app can be used to characterize the performance of a building subjected to excitation from a natural hazard event. The application focuses on quantifying building performance through decision variables. Some of the building features and natural hazard event characteristics are often available with limited accuracy or not available at all. The PBE app allows users to consider the uncertainties due to such imperfect information and propagate their effects through the analysis.

The seismic response of the structure can be estimated using the same modules that are avaiable in the SimCenter EE-UQ app. The PBE app builds on the EE-UQ app and uses its response estimation features to assess the behavior of a building under a seismic event. Users can also choose to import response estimates from external simulations and focus only on the damage and loss estimation in the PBE app. Performance of a building under other, non-seismic, natural hazard events can also be considered by loading external demand data.

In this application, users can characterize the seismic hazard, the structural model, the asset model, the demand model, the damage model, and loss models. All models are interconnected by a flexible probabilistic framework for uncertainty quantification. The calculation workflow starts with response estimation (e.g., nonlinear response history simulations) to obtain Engineering Demand Parameters (EDPs) that can serve as the demands for performance assessment. The component definitions in the Asset model are used to generate multiple realizations of the building with the prescribed component types and corresponding quantities assigned to each floor and direction. Fragility functions defined for each component type are then used to estimate component damage states throughout the building as a function of the demands calculated earlier. Finally, loss models are used to calculate the consequences of damages in each component.

Depending on the type of structural system, the complexity of the numerical model, and the desired sample size, the structural response simulations can be computationally prohibitively expensive. To overcome this impediment, the user has the option to perform the response simulations on the Frontera supercomputer. Frontera is part of the Texas Advanced Computing Center (TACC) and it is accessed through NHERI DesignSafe-CI, the cyberinfrastructure provider for the Natural Hazards Engineering Research Infrastructure (NHERI).

The computations are performed by a series of applications, a workflow. The PBE runs these applications using SimCenter’s backend engine. The backend takes the outputs from each application and provides them as inputs to following application in the sequence. Users are not limited to using the built-in applications. Advanced users can modify the backend and add their own application in the workflow. This allows them as well as other users to take advantage of the newly added applications.

This is Version 4.1 of the tool. Users are encouraged to comment on the additional features and capabilities they would like to see in this application through the github discussion page. We greatly appreciate all feedback. Features requested by one user are quite likely beneficial for many more in the community. Please review the lbl-requirements to see what features are already planned for future versions of this application.