MSC Software Corporation

Airframes are designed to deflect in response to aerodynamic and gravitational loads during flight. These deflections in turn load the mechanisms riding on the airframe that move the primary flight control surfaces to maneuver the aircraft. The airframe manufacturer must ensure that deflections of these mechanisms at any point in the flight envelope do not affect their operation. For example, the Airbus A400M elevator is connected to the horizontal tail plane (HTP) with eight hinges that form a straight line when the wing is undeformed. Seven of these hinges are floating hinges which can float in the hinge line direction. When the HTP structure is loaded, it deforms, deforming the hinge line. The multi body simulation (MBS) model here shows the location of hinge 7 which is used to move the elevator, and the drawing below the model shows a cross-section of the hinge. The gap g2 in the drawing allows the red lug to slide on the green pin.

”The replacement of the physical A350- 1000 wing bending test with simulation of the effects of deflection on the flight controls saved Airbus about €3 million and 4 months on the certification process for the A350,” said Michael Vetter, Project Leader Multi-Body Simulation with Airbus. Most of these savings were achieved by eliminating the need to build test fixtures. Similar savings will be achieved for each future aircraft model. Airbus engineers are also working to apply this same method to other mechanical systems of the aircraft such as landing gear and passenger doors.

• Saving significant time and costs by replacing expensive physical testing with Adams simulation
• Removing the limitation on the number of different load cases and configurations that could be tested by physical test rig
• The simulation results successfully correlated with all of the tests
• These results convinced European Aviation Safety Agency(EASA) that functional testing could be replaced with Adams simulation so simulation is used to certify the A350-1000 XWB wing

The primary function of heavy duty trailer suspensions is to link the trailer to its wheels. This provides a compliant connection which protects the trailer cargo from the shock and vibration inputs developed at the road surface. In addition, the suspension must meet the customers’ expectations for usable life, and do so while being economical to manufacture. One of the challenges of trailer suspension design is that these requirements often conflict with each other. Trade-offs are often required in order to meet these performance requirements over the suspension’s entire operating range.

“We can now simulate a new suspension, in a different trailer configuration, for a specific event, in a matter of hours as compared to the days or weeks that are required with physical testing,” Dr. Patterson said. “The fact that we can change the system much faster in the simulation than on an actual trailer makes it possible to evaluate the performance of our product in more configurations, all while spending less time and money building prototypes and performing physical testing. Of course, we always run a final physical test to ensure the accuracy of our simulations. The end result is that we are able to bring products to market faster, and generate larger revenues while reducing our product development expenses.”

• Simulation results make it possible to see every aspect of suspension behavior.
• Adams results match very closely with physical test measurements on numerous occasions comparing the tire loads, component forces, and suspension performance characteristics, such as ride height change.
• Simulation provides a much better understanding of how the proposed suspension design performs than can be obtained by physical testing.
• Loads determined by the simulation are used to design fatigue tests.

The defining characteristic of a zoom lens is that its focal length can be varied. The focal length determines the angle of view — how much of the scene will be captured — and the magnification —how large individual elements will be. The shorter the focal length, the wider the angle of view and the lower the magnification. The advantage of zoom lenses over lenses with a fixed focal length is that you don’t have to change lenses to achieve a tighter or a wider composition. Most zoom lenses, particularly those designed for consumer and professional photographers, lose focus when the focal length is changed. But high-end zoom lenses, especially those designed for producing films or television, can be zoomed in and out without losing focus. This type of lens is called a parfocal lens. The first parfocal lens capable of zooming in an out while maintaining precise focus to a degree acceptable for demanding cinema production was designed and built by Pierre Angénieux in 1956, a feat for which he received an Academy award for technical excellence. Parfocal zoom lenses are very difficult to design and build. Zoom lenses generally consist of three different groups; two of them are moving together (to change focal length) and the last one independently (to focus) and one stationary group of lenses with each group comprising two of more lens elements.

With the new method proven, Ayad simulated all of the company’s zoom lenses and found the worst-case position for each lens. Now inspectors are able to inspect the tilt simply by moving the lens to this position and making the measurements. The net result is that the time needed to inspect each lens has been reduced.

• Inspection time has been reduced
• Less experienced operators can perform the inspection
• Adams simulation accurately predict worst case position

It takes a 450 horsepower truck with an 80,000 lb. load roughly 90 seconds to accelerate to 50 mph but the brakes must be able to stop the truck in less than 5 seconds. Air brakes are used almost exclusively in heavy-duty trucks and trailers because they offer the following advantages. First, the air they run on is free. It only needs to be compressed, cleaned, stored and distributed. The air brake circuit can be easily expanded so trailers can be coupled and uncoupled from it. Besides providing the energy required to stop the vehicle, compressed air also signals when and with how much force the brakes should be applied in any situation. Finally, air brakes can be designed with sufficient fail-safe devices to bring the vehicle safely to a stop, even in the event of an air leak. Reinforced rubber hoses deliver air from fittings on the frame to brake chambers on the axles. In a typical tandem rear suspension there are typically 8 brake hoses plus additional hoses for the power differential lock and other features for a total of 11. The hoses must be routed through a tight space and accommodate the full range of steering gear and suspension travel. The hoses are required to avoid contact with components with sharp edges that might wear the hoses, maintain a specified minimum bend radius to avoid constricting flow within the hose, and avoid axial forces high enough to pull out the hose out of the fitting.

“Simulation makes it possible to try many different positions, orientations, and clipping options early in the design phase prior to the availability of a prototype,” said Stefano Cassara, Manager Vehicle Dynamics Simulation for Navistar. “New design iterations can be evaluated in a small fraction of the time required for physical testing. The new approach makes it possible to design new hose configurations in only about two weeks. Since the design process will be carried out early and outside the critical path we should be able to bring new vehicles to market six weeks faster than in the past. Another advantage of the new approach is that we can model loading scenarios, such as braking, that cannot be duplicated on the test rig.”

• Simulation of hose routing helps reduce time to market by six weeks
• Adams predictions perfectly matched test results in each steering position
• Simulation provides a much better understanding of how to route the braking hoses to avoid contact with components with sharp edges that might wear the hoses in response to suspension and steering movement
• New Adams FE Part provided a fast and accurate way to predict the large deformation of brake hoses in Adams environment

The vast majority of robots are controlled through the use of encoders that measure joint rotation. But even when encoders with very high levels of accuracy are used, the ability of robots to move to an absolute XYZ position and ABC orientation is limited by deflection, thermal expansion and manufacturing variation. Some applications, such as placement of a disk drive read head, require very higher levels of positioning accuracy that can only be achieved with a very expensive, special purpose robot. This challenge is being addressed with visual servoing technology that uses a vision system to acquire an image that determines the relative positions of the robot end-effector and the target.

“The concept of the hidden robot model is a powerful tool able to analyze the intrinsic properties of some controllers developed by the visual servoing community,” Sébastien Briot concluded. “Adams simulations have played an important role in validating our theoretical work on hidden robot models. The integration of Adams with Simulink through Adams/Controls eliminated the need for us to write complex equations for predicting the dynamics of parallel robots and also provided graphical results that gave us a better understanding of robot behavior.”

• Adams simulation accurately predicted position and orientation of the robot.
• Simulation played an important role in validating the theoretical work
• Complex equations are no longer needed to predict the dynamics of parallel robots

Reinforced plastics and composite materials are chosen more and more because of their improved performance regarding damping for NVH applications compared to current metals. Material specialists need to efficiently identify this mechanical characteristic which, like the stiffness and failure, is anisotropic and driven by local fiber orientations in the material’s microstructure. Moreover for NVH purposes, the frequency dependency must be clearly identified in order to provide accurate material models to design engineers.

• Available in < 2 days when using available constituent models
• Quickly evaluate various multiphase materials to identify the best candidates for NVH targets
• Avoid waiting time and unneeded cost of performing additional experimental tests for each candidate material

Discontinuous fiber composites (DFC) are produced by compression molding of prepreg chips which are made of a combination of unidirectional fiber and a Thermoset or ThermoPlastic matrix. In some cases, matrix is made of thermoset which consolidate through a chemical/ cure reaction at elevated temperature. However, when the curing cycle is not well monitored it can be observed some cracks that appear between the chips due to apparition of thermal stresses normal to two chips.

Due to their complex microstructure, these materials request the definition of new dedicated methods in order to capture accurately the local orientation and to compute the local homogenized properties in order to simulate correctly the curing and the design process. Hence, the Digimat platform is used to build a complete methodology to compute these residual stresses and to take them into account during the design cycle of the part.

• Propose a complete methodology to analyze Discontinuous Fiber Composites: Understand the effect of the local microstructure on the behavior of the part.
• Improve the understanding of the effects of the manufacturing cycle parameters: Evaluate the risk fo the apparition of defects between the chips for a given set of parameters of manufacturing (pressure, temperature histories). Though their nature is different, this procedure can be applied for both, thermoset or thermoplastic resin.

Designing lightweight CFRP structures with confidence requires access to allowables values. Allowables generation is extremely time and money consuming. Various layups, coupon tests and environment conditions must be covered for each characterized material system. Each test configuration must be repeated many times to obtain a statistical evaluation of the mechanical property.

Digimat-VA successfully predicted allowable values within 10% error for all cases except the soft open-hole tension scenario. Typical run times for unnotched tests were 3 minutes, while it look less than 10 minutes for open-hole cases.

Laminate T-stiffeners are widely used in the aerospace industry to transfer the 3D complex loads between the stiffeners and the skins. However, the way they are manufactured can affect the inherent properties.

In this case, we have considered that the stiffener and the skin were assembled using an RTM process but because of the poor infiltration of the resin due to the fiber orientation changings, some dry spots appear in the noodle. These dry spots or voids affect the mechanical properties of the noodle and this knock-down of properties must be taken into account during the design process.

With Digimat, effective modeling solution enables to understand the sequence of failure of the structure and the resultant load level. The results allowed to capture the progressive loss of stiffness of the structure and the resulting load.

Omni-Lite Industries is an advanced materials company. They recently designed a new part that was exhibiting a unique material flow. The part was cold formed out of 1100 aluminum material. The manufacturing process for this new part utilized a three-die progression, and was produced on a Nakashimada TH3-6A cold forming machine.

Omni-Lite found that there is a very accurate correlation between the software prediction of material flow and the real-world results from the heading tooling. The results prove that simulation is a very necessary tool to use for cold forming tool design in order to reduce development cost and product development lead time.

• Reduce product development costs
• Reduce time to market by eliminating need for repetitive physical testing
• Very close correlation between physical test results and Simufact simulation results

Omni-Lite is a rapidly growing advanced materials company that develops and manufactures precision components utilized by several Fortune 500 companies including Boeing, Airbus, Alcoa, Ford, Caterpillar, Borg Warner, Chrysler, and the US Military, Nike, and Adidas. To aid in its aggressive product development process, the engineering team began using the sophisticated finite element forging simulation software package Simufact.forming, from MSC Software.

It was found that Simufact.forming provides invaluable information at a critical time in the design process. The software provides the opportunity to see how design variations will work out prior to purchasing any tooling. It allows Omni-Lite to shorten its process development time considerably, and respond faster to customer requirements and design new products faster.

• Optimize manufacturing process to reduce development time
• Ability to respond more quickly to changing customer requirements
• Accelerated innovation due to faster design process

DEMA SpA is a major aerospace supplier that provides work packages for many major aircraft programs such as the Boeing 787, Airbus A380 and A321, ATR 42-72, Augusta Westland AW139, and Bombardier CS100. DEMA recently designed and built an innovative avionics bay pressurized door for a commuter jet. DEMA engineers developed an innovative design concept in which the door is assembled from sheet metal using a machinable plate that saves weight by eliminating the need for mechanical joints. DEMA needed to analyze the ability of the door to meet in-flight structural requirements in spite of multiple damage scenarios that might be incurred during service operations or could result from manufacturing variation in order to determine whether or not the structure maintains a sufficient safety margin. These damage scenario analyses are used as the basis for inspection protocols that are performed on a regular basis to ensure that the door is flight-ready.

“Editing the geometry for one scenario took only 4 hours, a 75% reduction from the traditional method,” said Antonio Miraglia, Stress Lead for DEMA. “Prepping the model took four hours, the same as the traditional method. A total of 8 hours were thus required to model each scenario and 32 hours were required for all four scenarios, a 60% reduction from the time required in the past.”

• Process of constructing 4 damage scenarios reduced from 80 hours to 32 hours
• Time to modify geometry reduced by 75%
• Solver validation further reduces the process from 80 hours to 26 hours

In a wide range of industrial and defense applications, materials are required to perform at extreme operating conditions involving large plastic deformation, high strain rates, elevated temperatures and severe dynamic pressure. For example, materials used in armor and antiarmor technology experience deformations of 500% and higher, strain rates up to 106 per second, temperatures above the material’s melting point and pressure of several gigapascals (GPa). Likewise, in industrial applications such as forging, hot rolling, extrusion, wire drawing and sheet metal forming, workpieces undergo plastic deformations ranging up to 100%, temperatures from 500oC to 800oC, strain rates up to 100 per second and pressures up to several hundred Megapascals (MPa). Other examples of applications where high deformations, temperatures, strain rates and pressures are experienced include perforating guns in the oil and gas industry, debris impact in aerospace engineering and ship collisions in naval engineering.

Now that TECHDYN has validated their material model and ability to simulate extreme conditions, the company is preparing to offer engineering consulting services using Marc with the new material model to provide accurate simulations of extreme conditions. “The ability to accurately simulate extreme conditions will help improve product performance by making it practical to evaluate many more design alternatives than would be practical using the build and test method while at the same time reducing product development cost and leadtime,” Bonora said.

• Reduce physical tests
• Improve accuracy of material behavior prediction
• Improve product performance

Power plant sites consists of numerous built up structures, each of which must be designed for positive margins of safety. Finite Element Analysis (FEA) is a common numerical method used for determining and improving the strength and dynamic performance of such structures. With an increasing need to find optimal power plant structural designs, the most efficient FEA workflows are critical. This case study discusses methods to expedite the FEA process, namely: rapid construction of Finite Element meshes from geometry and leveraging FEA technology to quickly connect hundreds of structural members.

Most industrial structures consists of hundreds of structural members, many of which have the common trait of being thin-walled. This boiler structure, part of a large power plant, is an example that is characterized by thin-walled members. Finite Element Analysis (FEA) is a common method used for strength analysis, but the large size of this structure presents a number of challenges that can delay FEA. The first challenge involves constructing the finite element model, and traditionally requires hours of work. The second challenge is adjoining numerous structural members together, but the process should be both rapid and without error. The use of MSC Apex for mesh construction and the use of MSC Nastran for analysis is demonstrated.

• MSC Apex accelerates the creation of midsurface geometry and FEM model
• MSC Nastran Glue Technology is leveraged to perform strength analysis on highly an interconnected structure

With annual production of 50,000 tractors, TürkTraktör is the largest producer of tractors in Turkey. The powertrains of the company’s tractors contain many gear pairs and gear groups that transmit torque through the system. For example, the transmission group includes spur and helical gear pairs. Next the torque is transmitted to the differential via a hypoid gear pair. After the differential, a planetary gear group reduces the torque. The torque is transmitted through shafts between gear pairs and most of the shafts are fastened with multiple bearings to the chassis.

With the simulation model validated, TürkTraktör engineers will begin using it as part of the design process. “We are planning to use simulation in future development projects to minimize lead time and cost,” Akce said. “We have concluded that we can accurately predict the results of a testing campaign that takes several months with only two weeks of simulation. The faster speed and lower cost of simulation will also give us the ability to evaluate more design alternatives than was possible in the past. This will make it possible to reduce the weight and cost of some parts and to increase the durability of others. Of course, the design will be subjected to durability testing as a final validation step.”

• Accurately predict the results of a testing campaign that takes several months with only two weeks of simulation
• Faster speed and lower cost of simulation will also give them the ability to evaluate more design alternatives than was possible in the past
• Adams Machinery Gear module was leveraged to quickly and easily model the gear pairs in the driveline system
• Bearing was conveniently generated using the Adams Machinery bearing library by referencing the product code