Fast and complex simulation

2 mins read

Tom Shelley looks at the problem solving ability of one of the showcase companies at the June NAFEMS event

Really complex simulation problems that involve a number of different physical effects require suitable software to solve them. When we talked to Tim Webb, director of marketing, communications and programs for Simulia. Simulia is mostly what was Abaqus, which was acquired by Dassault Systèmes in 2005. Webb described some of what can be done, saying: "It continues to expand mainly in the multi-physics domain and in its ability to model fluid-structure interactions. For example, a projectile penetrating a tank full of fluid." Other examples, he cited, included the modelling of a car tyre hydroplaning on water, and forcing ink out of an inkjet printer nozzle. In the production manufacturing arena, he mentioned the blow moulding of plastic bottles, including Tetrapaks. And in the electronics sector, he spoke of the modelling of drop tests of LCD screens and mobile phones. In the design of construction equipment, he cited the modelling of the flow of earth during digging with a backhoe. In medical the contact of cardiovascular stents with artery walls could even be modelled. These problems can now be run on up to 256 processor cores so, as Webb says: "What used to take three days now takes four hours." Fluid-structure interaction has allowed the evaluation of possible fluid leakage around a syringe seal, but rather more critically, extensive modelling has also been used in the design of a heart-assisting device called the C-Pulse, made by Sunshine Heart. This was invented by Dr William Peters, a cardiothoracic surgeon and research fellow at Auckland City Hospital in New Zealand. The device consists of a cuff that wraps round the aorta; the main blood vessel that carries oxygenated blood from the heart to the rest of the body. It inflates and deflates a membrane that presses on the vessel's external walls, making the aorta pulse in time with the heart, augmenting blood flow. A battery powered pump worn outside the body powers the device. Since reliability is essential for use on humans, extensive finite analysis was then undertaken in order to arrive as a device shape that has the least variation of strain amplitude and the maximum compressive strain during an operational cycle. The heart pump device is being developed under the direction of Scott Miller, manager of mechanical engineering, at Sunshine Heart. He says: "We have been running devices day and night literally for years now. The test machine requires regular maintenance because the C-Pulse keeps wearing the test unit out. "The device has presently reached the clinical trials stage." A certain amount of expertise is required in order to use the tools. Webb says: "If you are going to take advantage of everything from soup to nuts, you need to have a pretty good knowledge of physical behaviour. For example, Abaqus users typically have an MSc, or PhD." The acquisition of Engineous in 2008 has further extended capabilities of Simulia software, with the addition of its two key technologies, Isight, which allows the creation of simulation process flows that consist of a variety of applications, and Fiper, which is an add-on to Isight that enables users to distribute and parallelise computation across all available computer resources, and share results. Pointers * Simulia software is particularly good at modelling fluid- structure interactions * Its capabilities have recently been extended by the acquisition of Engineous with its Isight and Fiper capabilities that allow connection to other modelling applications and solving them using an array of machines, run in parallel