MSC Software Corporation

The subject of this case study was an effort undertaken within Fokker Space to lower the volume and mass of solar panel array designs. This culminated in the Curwin solar panel array concept which used a curved arrangement of solar panels (like a tape measure) instead of a separate backbone structure to reduce both volume and mass while retaining the required stiffness and high frequency response.

The goals for the simulation of the deployment were:

• Determine the important factors in a successful deployment
• Evaluate the initial design of the solar panel array
• Validate design changes to meet the requirements of a successful deployment
• Final validation of a design that resulted in a controlled and reliable deployment

MSC Software’s Adams was chosen to analyze the multibody dynamic process during the deployment. In the past, Adams has been successfully used within the spacecraft industry to model solar panel deployment.

• Lower volume and mass of solar panel array design
• Reduce costs from $10,000 per pound for a single satellite launched via heavy rockets to below $3,000 with new approach
• Realistic simulation to replicate on-orbit conditions during deployment

Designing the right tire for large wheeled vehicles used to haul coal and other materials in underground mines presents an enormous design challenge. Pneumatic tires present risks because of the danger of an explosion in a confined space while solid tires are associated with relatively large vibrations experienced by the driver. Big Tyre, a company that specializes in producing solid tires for mining vehicles, is developing a unique alternative which uses arrays of leaf-springs, typically made of composite materials, to provide performance similar to pneumatic tires without the risk of blow-outs.

Big Tyre is a manufacturer of solid wheels that are primarily used in underground mining vehicles. “Many mining companies have switched from pneumatic tires to solid wheels because of the dangers presented by pneumatic tires underground,” Louden said. “Mines underground have bolts sticking out of the walls that can easily cause punctures. Tires on heavy vehicles are inflated as high as 170 psi, so when they are torn or punctured a considerable amount of force is released. Due to space constraints underground, workers are often in close proximity to the tires so the potential for injury when a tire is torn or ruptures is a major concern.”

The design concept provides the flexibility and challenge of defining various design parameters including the number of springs in an array, thickness of springs, curvature of springs, length of springs, material properties of springs, geometry and material properties of the segments that the springs attach to on the outer diameter of the wheel, as well as many others. The design criterion is to provide a very efficient vertical loading for the size of the wheel while providing similar if not equivalent suspension to a pneumatic tire, with excellent torque capacity and lateral stability.

Compumod first conducted a nonlinear static analysis on one spring to correlate the model material properties with experimental data. The material properties were tuned to replicate the measured reaction force in the experiment. Then a nonlinear analysis was performed on the entire wheel to assess its strength. The wheel was given an enforced displacement of 150 mm which was solved in 100 nonlinear increments. The reaction force was then measured on the ground and graphed against displacement. The first negative slope indicated failure of the wheel at 252 kiloNewtons or 25.7 metric tons, which is well over the target of 16 metric tons. After the first collapse of the wheel, the contact between the springs and between the springs and segments added stiffness to the wheel and the reaction force increased again for increasing displacements.

“After seeing the benefits of the software, we decided to purchase Patran and Marc,” Louden said. “Compumod organized training for us in their Sydney office and handed over the models they created in the consulting project. We very quickly began designing the second full-size version of our design, and have been able to improve the design at a much faster pace than in the past. It even allows us to simulate driving maneuvers of the vehicles, including obstacles on the road.

Pilsen Steel, a leading producer of castings, ingots and forgings experienced difficulties with ingots cracking in a forging operation. The company contracted with COMTES FHT to investigate and determine the root cause of the formation of longitudinal cracks in 34CrNiMo6 steel ingots.

Traditional process involved cooling of the ingots after casting to between 500oC and 600oC, after which the ingots are placed in the forging furnace at temperature of 1100oC to 1200oC. COMTES used MSC Software’s Marc nonlinear finite element analysis (FEA) software to analyze the process of heating the ingots in the furnace and confirmed that heating the ingots in the furnace generated thermal stresses that later caused cracks to form during forging. Additional simulation studies also showed that increasing the temperature of the ingots by 100oC prior to putting them into the furnace reduced thermal stresses to acceptable levels. Pilsen Steel implemented this change and it eliminated the cracking problem.

• Realistic Simulation of the Multiphysics behavior of metal during manufacturing
• Elimination of cracking in final product reducing reject rate and improving product quality

Performing thermal analysis on the complete ingot workload requires determining the radiant heat transfer between the furnace and each of the each ingots with shading effects taken into account. Marc excels at this type of challenging multiphysics problem which is why it is our finite element analysis tool of choice

Tikal, COMTES FHT

Spinal injury and the gradual deterioration of spinal discs that lead to back pain or spinal disorders can be treated surgically. One of the most promising surgical options under continuous development is the use of artificial discs to replace the patient’s natural spinal disc. The materials used in these artificial discs are an important factor in the development of this technology. The discs must be made from materials that are safe to be implanted in the human body, do not cause allergic reactions, but also wear resistant and compatible with medical imaging (MRI for example). Fiber reinforced plastic composites are used more and more in today's orthopedic implants because of their resistance to wear and improved mechanical properties.

The challenge when designing implants that take advantage of reinforced plastics is predicting the manufactured material performance. The mechanical properties of an implant designed with fiber reinforced plastics can vary widely depending on the use of the material and how the implant is manufactured. The injection or compression molding process used to manufacture the implant will affect the fiber orientations throughout the part. Typical analysis assumes the material is isotropic for simplicity, but in reality the fiber alignment is continuously changing throughout the implant, resulting in a heterogeneous, anisotropic material. Poorly aligned fibers or not appropriately accounting for the fibers’ effect on material performance can lead to a softer or stiffer implant than designed, and even premature failure.

MSC Software’s Digimat produces a much more accurate prediction of the composite behavior for materials such as fiber reinforced plastics. The process is simple. Start with the same finite element model of the implant that is used for the existing analysis. Digimat will work with any major finite element solver. Next, request the injection mold simulation results from the manufacturer. This analysis is done to assure the implant’s mold has been designed properly for manufacture, but the results can also be used in the finite element analysis of the implant itself. To do this, use Digimat to map the fiber orientations, residual temperatures and residual stresses onto the structural analysis model.

Select or create an intelligent material model of the reinforced plastic using the tools provided by Digimat. The intelligent material model is a function of fiber orientations instead of a static value, allowing Digimat to adjust the material stiffness at every location throughout the implant. Finally, conduct the analysis as normal with one exception, the static value for material stiffness will be replaced by a Digimat material model.

Digimat takes care of tying the intelligent material into the analysis solution so that the analyst can focus on designing the implant’s performance, not guessing at which material property might give the best results.

The attention to material details result in much more accurate simulations that reduce test/ analysis iterations and improve performance predictions. In the case of the Medicrea design, the original isotropic simulation over-predicted the implant’s stiffness by as much as 170%.

The same simulation using a Digimat material model that accounted for both changes in fiber orientations as well as plastic deformations matched the test results almost perfectly.

• Cost and time savings
• Reduce test/analysis iterations
• Improve performance predictions by 170%

Noise is becoming a major obstacle to growth in air transport as increasing numbers of airports place restrictions on the amount of noise that can be generated by an aircraft during various phases of flight. Airbus is working hard to reduce aircraft noise such as by improving the nacelle acoustic liners used to minimize the fan noise radiated from the engine. The company has dramatically reduced the time required to design and evaluate optimized acoustic liners by moving to a simulation-based process using Actran acoustic simulation software developed by Free Field Technologies (FFT), MSC Software Company.

The acoustic liners that are built into the engine nacelle are fundamental in controlling fan noise. Acoustic liners present a major design challenge because they must address a large number of conflicting design requirements. Liners must provide high levels of noise reduction over a wide range of engine operating conditions and frequencies. Liners must also meet tight space restrictions and need to be as light as possible in order to limit fuel consumption. The liner is typically designed at a point when aspects of the airframe and engine are not completely defined so the liner design must be flexible enough to adapt to changes. The liner must be able to survive exposure to heat, cold, water, oil, and maintenance operations. Finally, the liner must be durable enough to deliver decades of service in the highly demanding aircraft engine environment.

Liners are typically manufactured in two or three curved segments that are assembled with longitudinal splices. Simulation with Actran and other numerical tools helped to reveal the substantial impact of splices on forward fan noise and these simulations were confirmed with physical testing. These simulations made it possible to compute the radiated noise fields under all relevant engine operating conditions and predict the noise reduction in certification conditions. The design of the zero-splice concept, through numerical simulation, made it possible to significantly reduce the fan noise and the acoustic discomfort.

Airbus developed an integrated numerical chain for Actran in order to streamline its use by acoustics engineers who are not numerical experts. The chain, called Automated Liner Optimization Chain for Nacelles Air Inlets and Exhausts (ANaNax), automates the simulation process from engine geometry to Actran results including prompting the user for all required information and performing validation checks on the data entered by users. “A typical optimization loop for the nacelle liner requires evaluation of 80 liner iterations and three flight conditions at a frequency range from 125 Hz to 5650 Hz which means we need to simulate several thousand different cases,” Suratteau said. “Robustness and accuracy of the simulations is critical so realistic 3D shapes, flows and boundary conditions are a must. ANaNax greatly reduces the time required for non- analytical experts to perform simulations and to check their work to be sure inputs are realistic. Computation time has also been drastically decreased by the implementation of a high performance computing (HPC) platform based on Westmere X5670 Infiniband technology with 5312 cores combined with the high scalability of Actran.

• Reduce product development costs by avoiding expensive post-design changes.
• Reduce test/analysis iterations
• Improve performance predictions

• Significantly improve the handling, comfort and fatigue life of vehicles
• Reduced stress levels in many parts, resulting in improvements in component life
• Identify potential problems early in the design process and make corrections on the virtual model

• Ensure the safety of the marine operations
• Reduce risks and costs of the wind turbines installation
• Anholt offshore windfarm to become the biggest offshore windfarm in Denmark

• Successfully check the model components and generate a final assembly of the model.
• Performed model pull-off loading using incrementally applied large displacements.
• Make results plotting easy using Marc post-processing features.

• Over 60% of all eye injuries are caused by blunt impact, i.e. impacts with objects of various kinds that do not cause a perforation of the globe.
• Based on evidence of a patient who, despite having undergone the removal of the vitreous, had a clear macular hole resulting from a blunt impact, it was decided to investigate this phenomenon in more detail in order to validate the various hypotheses of damaging mechanism with the help of a MSC Dytran simulation.

• The computational model of the ocular globe was generated starting from an average size human eye represented with the help of the code MSC Dytran.
• The preliminary results of the project indicate that the laceration of the retina mainly occurs due to the tension resulting from the reflection of compression waves in the moments immediately following the impact, and not necessarily due to the deformation of the whole eye.

• The availability of a reliable and validated model for the simulation enabled the research team to understand in detail the pathogenesis of the blunt impact phenomenon, which is particularly difficult to reproduce in a controlled and instrumented manner through physical tests in the laboratory.
• Practical applications of this study are to be found especially in the military industry, for example in the design of advanced security systems for personnel and for helicopter pilots in the event of a crash landing.

• Optimize the design of every component to ensure their ability to withstand loads and successfully perform their mission.
• Determine the bounding limit design loads that could be expected on every component.
• Ensure that there was no possibility of contact between the flight hardware.

• Quick verification of results
• Shorter product development cycle
• Cost saving