SIMULIA Community News
March 2016: Exploring the Power of Optimization
This Looks Like a Job for... Abaqus!
International participants all choose Abaqus during a biomechanical design competition
When given a choice of software programs to solve a challenging simulation problem, some of the world’s smartest young professionals in the fields of multi-scale modeling and biomechanical engineering all chose SIMULIA’s Abaqus FEA.
The occasion was the first-ever MultiSim Modelathon, which took place at the University of Sheffield, U.K. The unique event was the brainchild of Professor Damien Lacroix, Director of Research at the Insigneo Institute for in silico medicine. Competitors were faced with the task of identifying the best procedure to help a patient with bone-thinning osteoporosis of the femur in the upper leg. Participants were presented with several leading software packages with which to solve the problem and, says SIMULIA’s Clint Davies-Taylor, “We gave them a choice and all five teams picked Abaqus.”
Members of the winning team (Takashi Ishii, Solenn Le Pense, Luca Modenese, Claire Villette, Claudia Wittkowske) felt that using Abaqus was the obvious decision. “It was quite clear to us that the Abaqus interfaces with Matlab and Python allowed for a level of flexibility and process automation that proved very valuable,” says Villette. Other features of Abaqus that allowed the team to work at peak efficiency included the facility to import meshes from ScanIP and Simpleware (with density-based material properties), the ability to write and modify input files automatically, and the ease with which different cases could be simulated and compared. Abaqus’ visualization capabilities were also consistently remarked upon.
Davies-Taylor is proud of Abaqus’ dominance and believes it’s related to SIMULIA’s track record in medical applications. “There are cases where Abaqus is the only tool that will do the job and that’s why they have it at Sheffield,” he says. “Its porelasticity capabilities are particularly important for modeling bone and tissue.”
Although everyone chose to use Abaqus, the winning team was the one that employed it to best effect, coming closest to finding the optimum solution to the complex problem. Osteoporosis, also known as porous bone disease, is the deterioration of bone tissue, resulting in lowered bone mass. Often showing no apparent symptoms until a bone fracture occurs, osteoporosis is referred to as a “silent” disease. Although porous bone was originally thought to occur only in women, over two million men in the U.S. alone have been diagnosed, but women over the age of 50 are at the highest risk.
The Modelathon problem specifically required participants to find the ideal amount of cement to inject into the femur bone when its density is substantially lost due to osteoporosis; this is a routine treatment for patients, but it requires the injection to be made at the optimum time - if injected too soon or too late, the procedure can be problematic. Using Abaqus, the teams were able to pinpoint the injection timing for the best results. “It was a big task to complete in 48 hours!” says Davies-Taylor. When asked how it felt to finally solve the tough simulation problem, all teams responded with pride, some saying they felt “amazing” or “like a champion!”
Davies-Taylor explains the inspiration behind the Modelathon, the first event of its kind: “It was based on the idea of a ‘hackathon’ but in this case specifically aimed at biomedical simulation.” Although most competitors were from England, others came from France, Amsterdam and even Japan.
Participants stayed in University residencies and just two intense days were allotted for all Modelathon activities. The competitors were split into teams of five and were first given short presentations on the available software programs they could choose from. They were then briefed on the task at hand and went to work. In separate rooms the teams used their own laptops connected remotely to High Performance Computing servers to complete the three intensive challenges: creating a musculoskeletal model of the subject, developing a finite element model to predict strains in the femoral neck at multiple stages of the gait cycle, and simulating the injection of bone-cement treatment.
Because everyone selected Abaqus, SIMULIA sponsor Davies- Taylor got caught up in the intensity of the competition. “I was there from 8:30 a.m. until 9 p.m.” he says, “but the teams were up even later into the night.”
After completing the tasks, each team prepared a presentation for the judges of the competition. Each member of the winning team took home a £100 Amazon.com voucher as a reward for their hard work.
Winning team member Le Pense described the power of in silico methods: “You can use simulation to test whatever you want with no limits on funding or equipment…it allows experimentation with mathematical models, to visualize and test the physics in a controlled environment, and it’s very flexible.”
The value of simulation was appreciated by all the contestants. Comments from members of other teams included: “Simulation is much quicker and cheaper than experimentation,” “One simulation provides thousands of results,” “Multiphysics is getting closer to real life,” “Simulation allows for shared understanding between experts and the general public by using visual aids,” and “Simulation increases our depth of understanding and appreciation of the complexity of life— that’s cool!”
For More Information
The next modelathon will take place on 7-9 September 2016 at The Edge, Sheffield. Please email pmo(at)insigneo.org if you would like to attend this event.