Japanese Team Up on CAE for Plastic Mold Making

TOKYO (FNS)–Four Japanese firms in different industrial sectors–computer systems, plastics, computer-aided design (CAD) and injection molding equipment–have joined to provide computer-aided engineering (CAE) services for quick, low-cost plastic mold manufacturing.

Combined services provided by Toshiba Corp., Toray Industries Inc., Mitsui Engineering & Shipbuilding Co. Ltd. and Toshiba Machine Co. Ltd. were said to cover wide-ranging areas from plastic material and mold databases to injection flow simulation and numerical control (n/c) tape cutting.

Masahiko Kohnosu, a chief engineer at Toshiba’s engineering automation software department, said fast turnaround is becoming increasingly important in the manufacturing of plastic molds, and that “small lot, large variety” now is the name of the game.

“It took a year to convince the four companies, all of which are members of the Mitsui group of companies, to join in,” Kohnosu said. Previously, he said, such extensive, inter-industrial cooperation was unheard of, even in the mutually cooperative Mitsui company group.

Toray Industries, which makes 25 percent of its $4.1 billion in annual sales in plastics, contributed to build a database incorporating characteristics of hundreds of plastic materials, including “top-secret” fiberglass-reinforced plastics.

The group’s CAE system, built around a localized version of the Sun-3 workstation by Sun Microsystems, Mountain View, Calif., shows on the 19-inch color display how the flow of a certain plastic material in the injection mold would change under various pressures and how fast it would cool off.

structural Analysis Provided

Kohnosu said that, in addition to the simulation of plastic flow pattern and cooling speed, the CAE system also provides structural analysis of plastic products.

Mitsui Engineering & Shipbuilding, one of Japan’s pioneers in computer-aided design, was said to provide the CAD part of the integrated CAE System, including mold patterns database, mold structural analysis, cavity core design, cooling pipe design, flow path design and injection conditions, such as appropriate injection pressure.

Toshiba Machine, a leading maker of injection mold equipment, provides engineering support from the point of manufacturing technology, according to Kohnosu. He said Toshiba Machine has considerable know-how in the final part of the injection mold process–the injection itself.

Toshiba Corp. would act as the system integrator, offering two types of CAE services–one based on a 32-bit supermini and the other based on Sun Microsystems’ workstation.

He said Toshiba actually used the CAE system to design the plastic molds of a TV chassis.

Viewing Plastic Flow

“You can see in full colors how the plastic would flow into the mold, if undesirable bubbles would form, where cooling would start and how the mold would be affected, step by step,” he said. The Sun Microsystems workstation simultaneously shows a variety of simulation results on the screen, in its multi-window function, he said.

Although he was not certain as to what kind of design efficiencies and cost reduction would be achieved, Kohnosu said, “You can try more plastic materials, more injection patterns and more pressure patterns in the same period of time.”

The CAE system employs the solid modeling method called the “boundary representation method,” which was said to be appropriate to describe cavity patterns inside the mold.

The CAE system based on the workstation cost $33,000 for injection simulation software and $50,000 for mold design software. The minicomputer CAE system was said to cost twice as much.

Kohnosu said as the injection mold equipment carried prices in the $133,000-$200,000 range, its plastic injection mold manufacturing system, including a workstation, should be priced as much. He said efforts were made to lower prices for that end.

“Local users won’t pay more for mold manufacturing system than for injection mold equipment itself,” he said.

The Toshiba group in currently considering plans for U.S. marketing. Kohnosu said Sun Microsystems, which supplies the workstation to Toshiba, might want to include the CAE system as part of its third-party software offerings in the U.S.

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Effective as from 1 April 2006 SimulationX 2.0 - the newest version of SimulationX developed by ITI Dresden, Germany - is released. Various new features, functionalities, modules, and extensions enable engineers in the technical departments of medium and large enterprises, to develop, virtually test and analyze components and systems of arbitrary complexity. Improved highlights in SimulationX 2.0 are in extracts as follows.

* Significantly shorter start-up time.

* New user interface supporting XP Themes.

* Extended Model Libraries (e.g Power Transmission: rigid / non-rigid properties).

* New in the TypeDesigner: Modelica specification is completely supported.

Another improvement in SimulationX will be the Code Export: ITI models can be integrated as S-functions for instance into Simulink models.

The ITI C-Code Export with the Option S-Function automatically generates all necessary components.

Also, the automatically generated S-function can be pro cessed by the Real-Time Workshop (RTW) in order to generate code for any of the target platforms supported by the RTW.

SimulationX is a modeling and simulation platform for valuation of the interaction of all components of technical systems.

It is the universal CAE tool for analyzing of physical effects - with ready-to-use model libraries for, e g, 1D mechanics, 3D multibody systems, power transmission, hydraulics, thermodynamics, electrics, electrical drives, magnetics and many more.

Add-On software programs complement the SimulationX software for special applications, e g, the ITI EdgeDesigner 1.0 supporting the design of fluidic components especially hydraulic valves.

At the same time, the new Web site has gone live - and provide detailed and new information to be familiar with this unique powerful system platform.

In the ITI download area you can get your test version for free.

SimulationX users like DaimlerChrysler, PSA Peugeot Citroen, Siemens, HUSKY injection molding Systems, Bosch Rexroth, Moog, and Norgren are represented worldwide in all technical sectors.

With SimulationX a tool became available which allows an efficient and time-saving development of system solutions.

The user-friendly engineering tool reduces considerably development costs and minimizes expenses for cost-intensive prototype testing on the complete system.

http://www.manufacturingtalk.com/news/itv/itv102.html

Here’s why a German bus manufacturer is implementing computer-aided engineering (CAE) capabilities in its product development cycle.

Optimizing and verifying the body structures of urban buses presents on-going challenges to the designers at MAN AG in Munich, Germany. There are various specifications from public transit authorities, styling issues, and serious product liability issues to contend with. MAN’s customers, the public transit authorities in Germany, demand and get 10-and even 12-year warranties. “If something happens which is not covered by the guarantee, we have to fix it anyway or the agencies tell us they won’t buy any more of our buses,” said Dr. Ulrich Breitling, head of MAN’s analysis operations in computer-aided engineering (CAE).

MAN, which is Germany’s second-biggest bus builder, shipped about 2,000 buses in chassis in 1996. Half of them were exported. Most of the buses are assembled in a plant in Salzgitter with stamped components coming from a facility in Gustavburg.

One thing that makes buses similar to cars is that even though their service lives are becoming longer (in the case of buses, 15 years or longer), the life span of any given model is getting shorter due to rapid technical progress in design. Customers - in the case of buses, the urban transit officials - are also demanding modifications to standard vehicles. “These modifications and constant design changes pose difficulties for us because every bus MAN builds is different.”

High product variability is always a challenge when management must rely on standardization and simplification to maintain high quality in manufacturing operations. Ensuring the integrity, durability and reliability of each new bus body structure means the CAE environment is a demanding one.

What’s more, there is plenty of competition, which is driving MAN management to insist that the time it takes for a bus design to get into production - currently four years - be minimized.

“Schedules for development are very compressed, and there is actually very little time and money for analysis,” Dr. Breitling observed. “So it is not possible to develop the structural integrity required in modem vehicles without CAE tools.” A key CAE tool employed at MAN is ANSYS from ANSYS, Inc. (Houston, PA). Due to time and cost constraints, not everything is fully analyzed: “We always have to be careful to match the correct analysis effort to the problem. To decide how much analysis must be done on each part, we look at how complex it is and how close to its limits it will be in service.”

Most of the analysis is linear statics (less than 10% is nonlinear static); all of it is 3D. Linear statics is done with ANSYS superelements. ANSYS nonlinear is used for pure large deformation cases: wheel and axle movement, for example.

To simulate nonlinear behavior of a bus body in a rollover crash test, MAN uses ANSYS/LS-DYNA software. That package, which is an explicit solver, is also used for material nonlinearities and large deformations. This means that not only does it work for simulating crashes, but also for the metalforming processes involved in bus manufacture.

MAN also uses a multibody, dynamic simulation system called SIMPACK that was developed by MAN Technologie Corp. and the German aerospace agency DLR.

Development

To help assure that the vehicle structure is developed in a proper manner, MAN utilizes a simultaneous engineering approach. Early on, designers and analysts discuss what functions should be integrated for satisfying strength and stiffness requirements. Weight and cost reductions are two elements that play important roles in vehicle development. Although reducing manufacturing costs is a goal, it is second to reducing the risk associated with new designs and in cutting time to market. According to Dr. Christoph Schoettl, responsible for MAN’s bus analysis, “The variety of specifications, liability, and unforeseeable service conditions requires that MAN make its bus structures insensitive to variations within the manufacturing process.”

Much of the bus structure geometry is generated with CATIA from Dassault Systemes CAD software; I-DEAS from SDRC is also used. Geometry is transferred to the CAE system with IGES and the finite element mesh (generated by CATIA) is transferred directly. IBM RS/6000 and Silicon Graphics workstations are the hardware platforms.

To meet tight schedules, many of the designs are done in 2D rather than 3D, which means that it is necessary to recreate the geometries in ANSYS or in the I-DEAS geometry preprocessor. Each new bus body is analyzed as a whole using shell and solid representations. Depending on the amount of geometric information in the model, the first-pass analysis of a 12-m bus structure takes 500 to 1,000 man-hours - and that time can be doubled if severe problems are found in the structure design.

“With analysis we often find things we didn’t expect,” Dr. Breitling noted.

“The really important questions - such as whether all the major components out of about 10,000 parts are interacting correctly within this mechanical system - must be answered by theoretical analysis,” Dr. Breitling said.Yes, they do perform physical tests of the entire bus body, “But by then it is too late,” Dr. Breitling remarked.

http://findarticles.com/p/articles/mi_m0FWH/is_n7_v109/ai_19785140/pg_2