Virtually reality

Posted on 12 Mar 2009 by The Manufacturer

Behind engineers’ computer screens and CAD tooling menus, a fierce battle is raging. Multinational companies are investing millions of dollars into 3D computer aided design, or CAD, software, digital prototyping, freeform modelling and digital product life cycle management. Mid-range solutions are reaching up and the high-end players are reaching down to the SME market and everyone wants the same thing: your engineers. Will Stirling reports

Today it is possible for manufacturers and other professions to produce three dimensional designs of nearly anything, from a piggy bank to a space shuttle. These designs can be turned, milled, heated, cooled, pressurised, spun at 1,000 revs and drop tested from 100 feet. And all this can be done on screen, in a virtual environment. The technology used to achieve this simulation is powerful and comes in a few core incarnations with multiple variations. More manufacturers and engineers are making use of old 2D drawings by reusing them as 3D models, enabling the reactivation of gigabytes of dormant intellectual property. Perhaps most importantly in today’s economy, data management software can analyse how the design will perform across the product lifecycle, assessing how the product would work on a mechanical, sustainable and logistical / time-to-market basis. CAD is a mature market that has consolidated greatly in recent years from a fragmented base, which has driven innovation, competition and better products.

Less cardboard and glue
Make a circle on screen. Extrude it into a cylinder. Give the cylinder asymmetric wings and curve the wings down. Bevel the edges of your 3D shape, now tap bolt holes in both wings and rebate the circle body with a groove. Make five hundred more changes and you have your Version One digital prototype. To the uninitiated, 3D CAD modelling has remarkable powers. To those that know, this sketch is just an oversimplified example of a 3D CAD design process – so what’s the big deal?

Not so long ago, getting from this point to your preproduction, metal and plastic physical prototype would involve numerous card, foam, wooden (and metal and plastic) prototypes, hundreds of man hours and a lot of money. The physical testing of these prototypes is also very expensive. Now, digital prototyping technology can minimise the number of physical prototypes required to reach the production phase prototype, allowing design verification on screen. This saves thousands of pounds in time and materials, and several more benefits including improving time-tomarket, and reducing a company’s carbon footprint. And with a lot of CAD vendors acquiring analysis companies, the links between 3D product design and simulation are now blurring.

Digital prototyping is an increasingly big feature of CAD tools, and the vendor that is currently banging this drum the loudest is Autodesk, a US software developer best known for its dominance of the 2D design market with AutoCAD. Centred around its flagship product Inventor, in different versions depending on user requirements, the company is pushing its digital prototyping abilities with gusto, using state-of-the art presentations to illustrate the technology (see page 28). It can save a company thousands of pounds in physical prototype costs.

Simon Booker, marketing manager for CAD vendor SolidWorks says this technology is just one aspect of hundreds of applications of CAD modelling, but acknowledges its value. “I was involved in the software for designing the original Rolls-Royce Trent engines. Every prototype literally cost millions of pounds, so it really can reduce companies’ product development costs drastically.” CAD tools with simulation capability, such as SolidWorks Simulation and Autodesk Inventor, have increasingly complex simulation settings including fluid flow analysis and motion simulation. Inventor Professional 2009 includes new features such as dynamic simulation, stress analysis (FEA) and cable and harness design.

Autodesk, while starting from further back than some competitors in developing 3D simulation tools, is pushing its capabilities heavily. One of its case studies is Swedish flooring system provider HTC’s concrete floor grinder (see left). The digital prototyping for this product in Inventor meant that HTC reduced the number of sets of physical prototypes from five to one. With the cost of a research prototype for its top product being nearly $500,000, the software investment is easily justified.

Growth industry
The 3D CAD software market, comprising four or five big global software developers and several smaller vendors, is mature and competitive. Notwithstanding the affects of a recession, it is growing too as architectural and engineering firms that have traditionally worked in 2D convert to 3D, digital prototyping gets more popular and more manufacturers and educational facilities invest in technology they see has a visible return on investment.

The ability to reuse, or rejuvenate, old 2D CAD files using 3D software is attractive to companies which perceive they extract more value from these designs. But are there compatibility issues with using, e.g AutoCAD files, with non-Autodesk products? While virtually every 3D CAD tool on the market can receive files in .dwg and .dxf format, the standard 2D formats, integrating data between different tools can be a concern for users. “The interoperability of all these systems is a big issue, as different departments and parties pass a design along the line,” says Richard Blatcher of Autodesk. “Autodesk owns AutoCAD, which has the most CAD seats [licenses] in the market, so there are no compatibility issues with using these files in all our products.” However, all the main vendors have developed their software with this in mind, knowing that designs created in one tool are migrated to another when a design is sent through the production process from design engineer to manufacturer, into a data management system which will manage that data across the company, and between companies.

Design without constraints
Parametric, history-based modelling requires the operator to use what is referred to as “design intent”, which covers the bulk of CAD tools on the market. The objects and features created are adjustable but constrained by real engineering design limits. Any future modifications can be simple, difficult, or nearly impossible, depending on how the part was designed. More software packages are being developed that provide the ability to edit parametric and nonparametric geometry without the need to understand or undo the design intent history of the geometry by use of direct modeling functionality. This means an operator with less training than a CAD expert can make certain, simple modifications quickly without recourse to, eg a subcontracted CAD operator. Called direct, dynamic or freeform modelling, some see it as the future of CAD for many applications where small and rapid changes to a design are required. “With for example SpaceClaim [direct modeling tool], you can pretty much import any CAD file from any system and can alter and edit that geometry almost like its clay,” says Martyn Day at X3Dmedia, a CAD media company.

PTC, one of the longest established CAD vendors, developed one of the earliest versions of direct modelling in the 1990s. Now direct modelling’s popularity appears to be resurgent, as successful tools like SpaceClaim, Siemens Synchronous Technology, and soon Autodesk Inventor Fusion, are being adopted.

Exponents of parametric modelling point out this approach has several advantages over the freeform approach. These include the ability to capture design intent and the ability to create families of parts and assemblies and parametric model variants. “We have overcome many of the traditional challenges of parametric modeling by the use of SolidWorks Intelligent Feature Technology (SWIFT),” says SolidWorks’ Booker. “This lets designers and engineers achieve the full benefits of a parametric design approach without the need to become CAD experts.”

Training and time
All the main vendors provide operator training, mainly via their authorised resellers. For products like Inventor and SolidWorks Simulation, this is normally four to five days, with top-up training provided as required. Vendors say training provides good value for money. IMASS Design Solutions, an Autodesk reseller, provides a fourday Inventor foundation course for about £1,200 per head, as well as software support and maintenance, implementation and telephone support. “Depending on what the client actually designs and manufactures, we would expect a return on this investment after a period of between nine and 12 months,” says Colin Watson, business development director at IMASS.

The issue of whether to train operators internally, externally or to subcontract design to third party designers is important and in UK manufacturing there are many examples of each solution. CAD software is complex, extremely powerful and requires a lot of training to be fluent, which is expensive. For example, Catia V6, the latest version of one of the most capable tools in the market and a product favoured by some aerospace and car companies, is a case in point. As more architecture firms adopt highend CAD tools, good operators are prized. “A good Catia or [Siemens] NX operator costs a lot of money,” says X3Media’s Day. “Some companies have thought about investing in it – it’s not the software cost that’s stopped them but the fact if they train anyone up they’re going to lose them to a different part of the market very quickly.”

Depending on the complexity of a product design that a company needs to develop, and the number of modifications it expects to make, direct editing tools can provide a solution to training costs. “Training in SpaceClaim takes from half a day to a day,” says John Milne of WhiteSpace Technologies, possibly longer depending on aptitude. “There are five million engineers world wide, only three million of whom operate CAD. The rest of the people in the process don’t have time to learn it, they don’t want to be a CAD jockey. Direct modelling is for them.”

High-end CAD and convergence
At the top end of the market, tools like Siemens NX, Dassault Systéme’s Catia and PTC’s ProEngineer continue to have a firm grip on the car and aerospace industries, as the level of simulation and productivity enhancements are generally superior to the mid-range tools. A license for the base package in this group is in the £5,000-£6,000 range, and add-on tools can take a package to over £8,000. Catia brought out version six, V6, at the end of last year. Catia provides enhanced ‘live collaborative design’, where multiple users can contribute to a design ‘simultaneously’, and the new version offers faster data sharing irrespective of distance, a new easy-to-use interface and a powerful new underlying ‘kernel, or solid modelling component. The ‘bird’s nest’ Beijing Olympics Stadium was designed in Catia. Siemens NX has a strong foothold in high performance automotive, for example NX6 is used by the RBS Williams Formula One team. Siemens PLM Software hold regular technical master classes where license owners can get top tips from prestigious clients, like Williams’ engineers. PTC’s ProEngineer has a strong reputation for powertrain simulation. “For powertrain applications it’s a very competent product, a lot of very serious engineers use ProEngineer,” says Day at X3Dmedia. PTC’s history is interesting. It was the first company to really perfect parametric modeling, but when it began focusing on PLM software it lost market share in its traditional CAD stronghold. Now it is fighting its way back with ProEngineer.

The market trend in CAD today is that product performance has improved across the board, and convergance as the market consolidates. Some say this will stop now the recession has arrived, but tools are under pressure to continue to offer more functions in the basic package. The mid-range tools such as Inventor and SolidEdge are reaching up to appeal to the automotive and aerospace industries and the high-end tools reach down, to appeal more to SME manufacturers, smaller engineering firms and architects. It will continue to evolve as freeform modelling, PLM and digital manufacturing simulation becomes more pervasive.

Digital prototyping is an example of an application that should attract attention at the moment, when cost-saving benefits of making fewer prototypes, reducing waste and improving time-to-market is crucial. “The marketeers have been telling us for years that time-to-market and product design innovation are key areas for success, says X3Dmedia’s Day. “In times of economic growth, there was room for inefficient processes and substandard products; but in a new economic landscape, surviving and indeed excelling in the field will depend on new efficiencies and innovation.”