FabSim3: An automation toolkit for verified simulations using high performance computing

A common feature of computational modelling and simulation research is the need to perform many tasks in complex sequences to achieve a usable result. This will typically involve tasks such as preparing input data, pre-processing, running simulations on a local or remote machine, post-processing, and performing coupling communications, validations and/or optimisations. Tasks like these can involve manual steps which are time and effort intensive, especially when it involves the management of large ensemble runs. Additionally, human errors become more likely and numerous as the research work becomes more complex, increasing the risk of damaging the credibility of simulation results. Automation tools can help ensure the credibility of simulation results by reducing the manual time and effort required to perform these research tasks, by making more rigorous procedures tractable, and by reducing the probability of human error due to a reduced number of manual actions. In addition, efficiency gained through automation can help researchers to perform more research within the budget and effort constraints imposed by their projects. This paper presents the main software release of FabSim3, and explains how our automation toolkit can improve and simplify a range of tasks for researchers and application developers. FabSim3 helps to prepare, submit, execute, retrieve, and analyze simulation workflows. By providing a suitable level of abstraction, FabSim3 reduces the complexity of setting up and managing a large-scale simulation scenario, while still providing transparent access to the underlying layers for effective debugging. The tool also facilitates job submission and management (including staging and curation of files and environments) for a range of different supercomputing environments. Although FabSim3 itself is application-agnostic, it supports a provably extensible plugin system where users automate simulation and analysis workflows for their own application domains. To highlight this, we briefly describe a selection of these plugins and we demonstrate the efficiency of the toolkit in handling large ensemble workflows

Tutorial applications for Verification, Validation and Uncertainty Quantification using VECMA toolkit

The VECMA toolkit enables automated Verification, Validation and Uncertainty Quantification (VVUQ) for complex applications that can be deployed on emerging exascale platforms and provides support for software applications for any domain of interest. The toolkit has four main components including EasyVVUQ for VVUQ workflows, FabSim3 for automation and tool integration, MUSCLE3 for coupling multiscale models and QCG tools to execute application workflows on high performance computing (HPC). A more recent addition to the VECMAtk is EasySurrogate for various types of surrogate methods. In this paper, we present five tutorials from different application domains that apply these VECMAtk components to perform uncertainty quantification analysis, use surrogate models, couple multiscale models and execute sensitivity analysis on HPC. This paper aims to provide hands-on experience for practitioners aiming to test and contrast with their own applications

Behaviour of C-shaped angle shear connectors under monotonic and fully reversed cyclic loading: An experimental study

This paper presents an evaluation of the structural behaviour of C-shaped angle shear connectors in composite beams, suitable for transferring shear force in composite structures. The results of the experimental programme, including eight push-out tests, are presented and discussed. The results include resistance, strength degradation, ductility, and failure modes of C-shaped angle shear connectors, under monotonic and fully reversed cyclic loading. The results show that connector fracture type of failure was experienced in C-shaped angle connectors and after the failure, more cracking was observed in those slabs with longer angles. On top of that, by comparing the shear resistance of C-shaped angle shear connectors under monotonic and cyclic loading, these connectors showed 8.8-33.1% strength degradation, under fully reversed cyclic loading. Furthermore, it was concluded that the mentioned shear connector shows a proper behaviour, in terms of the ultimate shear capacity, but it does not satisfy the ductility criteria, imposed by the Eurocode 4, to perform a plastic distribution of the shear force between different connectors along the beam length.</p

Comparison of behaviour between channel and angle shear connectors under monotonic and fully reversed cyclic loading

Channel shear connectors are used to transfer longitudinal shear forces through the steel-concrete interface in composite beams. Angle shear connectors without bottom flange compared to channel shear connectors could be cheaper and more economic by saving more steel material. This paper presents an experimental evaluation for comparison of the behaviour of channel and angel shear connectors under monotonic and fully reserved cyclic loading based on 16 push-out tests. The connection shear resistance, ductility and failure modes are presented and discussed. By comparing the channel and angle shear connectors, it was concluded that angle shear connectors showed 7.5-36.4% less shear strength than channel shear connectors under monotonic loading and 23.6-49.2% under fully reversed cyclic loading. Connector's fracture type of failure was experienced for both channel and angle connectors. After the failure, more cracking was observed in slabs with channels compared to slabs with angles. Furthermore, in despite of sufficient ductility for all channel connectors, angle connectors showed less ductility. The results indicate that the angle shear connector gave good behaviour in terms of the ultimate shear capacity; however, this type of connector cannot satisfy the ductility criteria imposed by some codes. In the end, the shear load capacities obtained from the experiments are compared with those suggested by the design codes.</p

FabCovidsim

This is a FabSim3 / EasyVVUQ plugin for Covid-19 simulation. It was used to compute the ensembles of the following paper: Edeling, Wouter and Hamid, Arabnejad and Sinclair, Robert and Suleimenova, Diana and Gopalakrishnan, Krishnakumar and Bosak, Bartosz and Groen, Derek and Mahmood, Imran and Crommelin, Daan and Coveney, Peter, The Impact of Uncertainty on Predictions of the CovidSim Epidemiological Code, 2020