MSC Software Corporation

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

Andolu Isuzu’s new 12 meter long bus, called the Citiport, is equipped with a ZF 6-speed full automatic transmission and a 6 cylinder common rail turbo diesel Cummins engine that produces 283 horsepower at 2100 rpm. The bus can be configured to hold up to 103 people. A wheelchair ramp and kneeling system simplify entry and exit for passengers with disabilities. The bus uses an independent air suspension powered by an electric or engine-driven air pump or compressor. This compressor pumps the air into a flexible bellows made from textilereinforced rubber. The air pressure inflates the bellows, and raises the chassis from the axle. There are two air suspensions in the front of the bus and four in the rear.

With the aid of simulation results, Anadolu Isuzu engineers were able to dramatically improve the initial design concept. For example, the optimized suspension design parameters developed in the simulation reduced the rollover risk by 8.37%. The fatigue life predictions highlighted excessive stress in several body components. These components were redesigned to meet design specifications. “The use of simulation reduced the cost of the product development process because fewer physical prototypes and less physical testing were required,” Sert said. “Simulation also reduced the time required to bring the new product to market. The product was introduced about one year ago and has become a major success in the export market.”

• The optimized suspension design parameters developed in the simulation reduced the rollover risk by 8.37%
• Simulation also reduced the time required to bring the new product to market, which is a major success
• The predictions of the simulation model closely matched the results of actual measurements

Many structures in plant engineering are characterized as thinwalled. The Finite Element Method (FEM) is a common method used to assess the performance of such thin structures. Creating a FEM model of a thin structure involves midsurfacing models and meshing with shell elements. However, the process for creating FEM models is time consuming often requiring hours and days. The use of MSC Apex can help produce midsurface models significantly faster than with other traditional CAE pre/post processors. In addition to FEM creation, MSC Apex can be used to perform strength analysis.

• Geometry is easily edited to construct FEM models rapidly
• FEM models are validated for materials, properties, mesh congruency, connections and boundary conditions
• FEM models may be exported from MSC Apex and used in a separate pre/post processor

The predominant forest harvesting method used in northern Europe is cut-to-length logging (CTL). CTL is based on a two machine solution – a harvester is used for felling, delimbing and bucking trees and a forwarder carries the logs from the harvesting area to a roadside loading area where they can be picked up by a truck. These are both off-road machines with a frame mounted crane that operate in areas not accessible by conventional wheeled vehicles at low speed. In order to stay competitive, the Swedish logging industry needs to increase productivity by 2% to 3% per year.

“Now that we have validated the ability of Adams to accurately simulate the performance of forwarders, we will be able to evaluate new design alternatives and optimize the performance of concept configurations in a fraction of the time required by the build and test method,” Ismoilov said. “The ability to evaluate more designs in less time will make it possible to optimize the suspension and other components of the vehicle in order to provide higher productivity without causing discomfort to the operator or damage to the soil.”

• The Adams simulation verified different suspension configurations in terms of operator comfort and impact on the soil
• The analyses results correlates well with physical tests on roll rate and other parameters
• Adams provides the ability to evaluate more designs in less time to optimize the suspension and other components of the vehicle

Noise regulations in a key Latin American country were revised to a lower level, forcing CNH and other construction equipment manufacturers to reduce the noise footprint of their products.

“Simulating the acoustic performance of alternative approaches to noise remediation helped us meet the tighter noise specification in about three months,” Tamamidis said. “If we had to rely on physical testing for this project, it would have taken at least a year to reduce noise to the levels needed to meet the new spec. Due to successful projects such as this, we have integrated Actran into our product development process and use it on a regular basis to help ensure the acoustic performance of new designs and solve problems with existing designs.”

• Quicker understanding of noise contributors
• Simulations proved more comprehensive than physical test
• Met noise specifications faster
• Able to ensure acoustic performance of new designs

Many design targets must be achieved before commercial vehicles such as trucks and buses are released to the market. An optimal design is one that best balances the many competing project targets: performance, regulatory, ergonomics, time to market, cost, warranty and others. Exploring potential design alternatives by building and testing physical prototypes is extremely time-consuming and costly. Instead, Ashok Leyland engineers use Multibody Dynamics (MBD), durability, crash and safety, Computational Fluid Dynamics (CFD), and Noise Vibration and Harshness (NVH), Computer Aided Engineering (CAE) tools to evaluate the performance of a wide range of design alternatives. After identifying the optimal virtual designs that meet the design targets, engineers move forward to build and validate the vehicle for the launch. This approach reduces engineering expenses, accelerates delivery to market, and meets or exceeds customer requirements.

With respect to the savings for the overall activities of the CAE across all the domains, there is realization of savings of 15% on Preprocessing, 80% in Post-processing in Crash, CFD, Durability and NVH with the automation implemented through SimManager. About 60% savings in human effort is achieved in durability studies.

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

Latches with child safety locks are built into the rear doors of most automobiles to prevent the passengers in the rear seats from opening the doors of the vehicle while the vehicle is moving or at rest. The child safety lock is a mechanism that temporarily disables the operation of the inside door handle. When the child safety lock is engaged, the rear doors can only be opened from the outside. On newer models, this safety lock is activated or deactivated electronically utilizing a small motor within the side door latch by a switch, typically located near the driver’s side door lock switch.

Using multibody dynamics simulation, Kiekert engineers dramatically reduced the time required to design the child safety lock mechanism to only about three weeks. The child safety lock is part of a side door latch that is still in the development process but previous projects have demonstrated that the use of simulation – including finite element analysis and tolerance analysis in addition to multibody dynamics – can substantially reduce the time required to bring a new latch to market to less than 18 months.

• The Adams simulation dramatically reduced the time required to design the child safety lock mechanism to only about three weeks
• Kiekert accurately characterized the performance of proposed design iterations using engineering simulation prior to the prototyping phase
• Using Adams flexible body, they precisely captured the deformation of the plastic levers and how that affects the system performance

The Saab Skeldar V200 is a unique entrant in the unmanned aerial vehicle (UAV) market which is dominated by fixed wing aircraft. As a rotary wing aircraft, the Skeldar does not require runways to take-off or land from and can hover in one position. Skeldar is designed for land- and sea-based patrol, light transport, electronic warfare and surveillance applications. With dimensions of 4 meters long by 1.3 meters high by 1.2 meters wide, the UAV flies at speeds up to 130 km/h with a range of 150 km.

After validating the model, Persson applied it to the issue that had been experienced with the prototype and discovered that the simulation model accurately duplicated the behavior seen in the prototype. The simulation model provided far more detailed information than could be obtained by instrumenting the prototype, such as the aerodynamic forces acting on each section of the blades. The model also made it possible to evaluate the performance of the UAV under a much wider range of conditions than could ever be evaluated with the prototype due to the time, cost and risks involved in actual test flights.

• Leverage Adams simulation to accurately capture the interactions between the lifting forces on the rotor blades and downwash
• Use multiple-flexible part method to capture the large deformation of the rotor blades during the flight
• The aerodynamic forces and moments acting on the UAV are incorporated into the Adams model as a user-defined function
• Adams analysis results correlates well with physical tests regarding flight behavior
• Adams simulation saved the team at least 6 months compared to the traditional approach

A vehicle might be subjected to misuse, peak load or strength events such as driving over a curb or skidding against a curb a few times during its life. These durability load cases play a major role in the product development process since they potentially drive the design for several components. At Volvo, the “driving over a curb” and “skid against a curb” strength events are classified into two categories, Level 1 and 2. Level 1 represents extreme customer usage and the requirement is that all functions remain intact with no visible or noticeable deformation of any component of the vehicle. Level 2 covers customer misuse and a certain amount of damage is accepted with a safe failure mode. Structural deformations are acceptable but there should be no separation or breakage. For level 2 it is desirable that a predetermined inexpensively replaceable component deforms and protects neighboring components, a design principle known as chain of failure.

The ability to accurately simulate Level 2 load cases will make it possible to substantially improve the product development process. “From the early stages of the development process, we will be able to evaluate the performance of alternative designs in terms of their performance under Level 2 loads,” Wirje said. “The ability to quickly and easily look at alternatives at a time when we are not locked into any particular approach should make it possible to meet performance requirements with a lighter suspension that can improve the fuel economy of the vehicle. At the same, we should be able to reduce the cost and time involved in suspension development by performing product development more accurately from the beginning so fewer prototype verification cycles are required. Of course, full physical verification will be performed at the end of the project.”

• Leverage Adams-Marc to capture plasticity and buckling of flexible lower control arm in the suspension system
• The low velocity impact (Level 1) and high velocity impact (Level 2) cases showed the same behavior as the physical tests
• Be able to meet performance requirements with a lighter suspension that can improve the fuel economy of the vehicle
• Reduce the prototype verification cycles by performing product development more accurately from the beginning

The stringent acoustical requirements imposed by the Belgian standard for dwellings (NBN-S01-400-1 (2008)) present a major challenge for architects. In particular the standard defines strict requirements for the global sound insulation between rooms which is mainly determined by the direct transmission and flanking transmissions in which sound waves produced in one of the rooms excite the flanking structure and generate structural waves which are transmitted through the structure.

BBRI researchers evaluated the incumbent and new prediction formulas over a wide range of surface mass ratios in the case of the old formula, and ratio of characteristic moment impedances in the case of the new formula. The results showed that for in-line and corner transmission in T-junctions, X-junctions and H-junctions the new formula more accurately predicts Kij. This work shows that a best prediction of Kij can be obtained by using the ratio of the characteristic moment-impedances “A” instead of the ratio of surface masses. It seems logical that the attenuation of vibration depends on this new ratio since during a change of direction only moments and angular velocities can participate in energy transmission.

• Accurate vibro-acoustic modeling of room to room vibration transmission
• Reduce product development costs by avoiding expensive tests

A common mechanical failure in optical systems is inadequate stiffness in the supporting structure. Stiffness is crucial for maintaining the alignment of the optical elements and achieving adequate optical performance. It is the responsibility of the mechanical engineer to provide adequate stiffness in the mechanical design.

In the first days the mechanical engineer analyzed the optical performance of the proposal’s mechanical design, identified and implemented needed refinements and validated that the resulting conceptual design could be developed into a detailed design that would meet the project’s optical requirements. Further, by working in simple, early structural models (lumped mass, beam and shell elements) as well as the large models of a more mature design (meshed and CAD joined tetrahedral solids), AEH/Ivory provides the project a continuous and traceable record of the adequacy of the structural stiffness supporting the optical system.

• Saved months of schedule time on projects
• Hundreds of thousands of dollars saved
• Assurance from the very beginning of the mechanical engineering effort that the structure is designed correctly

Regulators are continually increasing the performance standards required of automobile manufacturers. An example is FMVSS 105 and 121 which define the performance of braking systems and are intended to ensure safe braking performance under normal and emergency conditions for heavy trucks and trailers. A typical change in these regulations is to reduce the distance required to stop the truck under emergency conditions. This can be achieved by designing bigger, heavier, more expensive brakes. Ragnar Ledesma, Principal Engineer for Meritor, took a different approach by addressing the algorithms used to control anti-lock braking systems used in nearly all medium- and heavy-duty trucks.

The simulation showed the proposed control system brings the vehicle to a complete stop in less than 4 seconds in a stopping distance of 177 feet (54 meters), demonstrating a way to meet the requirements of a tougher regulation without major changes to braking hardware. The results show a nearly constant deceleration response at the driver seat as opposed to the cyclical response with conventional ABS braking. The explanation for the improved performance is explained by the simulation results. The wheel angular velocities and tire slip ratios do not fluctuate from their desired values, hence the new ABS control system can sustain maximum braking forces almost over the entire braking cycle.

• Leveraged Adams-Controls Integration to provide virtual testing of the new braking algorithms used in the ABS system
• Achieved a reduction in truck stopping distance by over 30% using current disc braking systems
• Evaluated the truck braking performance without many expensive prototypes iterations

Comat Aerospace is in the process of developing the 3POD Antenna Pointing System (APS) in collaboration with the Centre National d’Etudes Spatiales (CNES), the French national space agency. The role of the 3POD APS is to keep the antenna pointed at ground stations regardless of the satellite’s orientation while maintaining low mechanical jitter to ensure line of sight stability. For its first projected deployment on the OTOS satellite, the 3POD ATS will be required to provide a 74° pointing domain with a worst case pointing precision of +/- 1° at a pointing speed of about 5° per second.

Comat engineers originally used Adams to perform kinematic simulation of the motion and piloting functions of the robot and to complete a parametric study on the various design parameters and their impact on the overall performance. But incorporating flexibility into the Adams model required a long design loop between the CATIA model, Adams model and Nastran/Patran model. By the time this design loop could be completed, the design had often been changed so the results were outdated. Going further in the process, Comat engineers built a prototype of the robot that highlighted the importance of the flexibility of the elements on its overall rigidity in certain positions.

• Study various design parameters
• Accelerate the design cycle
• Modify the design and validate the performance in about 4 hours