CAD/CAM system is now more powerful, easier to use.

CAD/CAM Systems Is Now More Powerful, Easier To Use

A range of enhancements for the I-DEAS CAD/CAM software from Structural Dynamics Research Corp. (SDRC), Milford, Ohio, is intended to increase design engineering flexibility and productivity, further automate the analysis function, enhance performance, and make the system easier to use. The improvements include new capabilities for the I-DEAS software for injection mold analysis.

According to SDRC manufacturing product manager Russel Stay, I-DEAS Release V (which just became available last month) now employs what's said to be a more flexible, intuitive approach to design. This "variational design" approach to solids modeling allows the user to sketch out a crude design and then add constraints--i.e., he tells the computer that those roughly sketched lines are actually parallel, perpendicular or tangent to each other. The software can simultaneously solve the equations that represent those constraints and generate the desired design.

Dimensions can also be added later to a rough sketch, and the sketched design will be automatically "corrected" to reflect those added dimensions. Thus, one line that is intended to be 2.3 times as long as another line does not have to be drawn exactly that way at first, as it can later be defined as such through dimensioning.

Another feature is "free geometry'" capability--allowing the user to work entirely without dimensions for the time being. For example, you can "extrude" a 3D shape from a 2D precursor without dimensions--something that not all CAD systems will permit, say company sources.

"Features-based modeling" is another new aspect of the system. The user can create a geometric element of a mold or part design--a boss, for example--and store it in memory as a "feature," which can be added as a standard element to later designs. Eighteen such features are supplied in a standard library, including bosses, through holes, countersunk and counterbored holes, and pockets with straight sides or draft angles. The user can define new features to add to the library.

SDRC has also enhanced the sculptured surface modeling capabilities in I-DEAS to facilitate the design of complex parts. A new capability for moving-mechanism analysis is also provided through an integrated kinematic solver.

SINGLE-COMMAND FEM 

SDRC has further enhanced the automated analysis capabilities of I-DEAS. It's now possible to generate a finite-element mesh (FEM) directly from a solid model with a single command. That task can now take minutes instead of days.

Also new is on-screen 3D dimensions for solid models--something that SDRC sources say is relatively new to CAD/CAM systems. The new software also allows you to run 3D rotations in software on less expensive 2D hardware.

A new user interface offers many convenient features, such as pop-up windows, cascading menus, user-definable icons, and dialogue boxes. The interface also provides a consistent "look and feel" on different hardware systems, to reduce training requirements among users of a variety of computers.

ENHANCED MOLD ANALYSIS

As previously reported (PT, March '90, p 14), I-DEAS now provides simultaneous simulation of mold filling and mold cooling, rather than segregating them as separate steps, which is said to provide greater accuracy and detail. Analysis of more complex geometries is now said to be possible, thanks to double the previous maximum number of finite elements handled by the system. Improved computational efficiency reportedly performs mold filling and cooling analyses two to 10 times faster than before, depending on the complexity of the job.

Other enhancements include warp and shrink analysis, predicting quantitative deformations from molded-in stresses, and degree of sink as a percent of total thickness. Packing simulation is also new, providing more accurate predictions of total clamp pressure requirements and of how much material will be required to fill the cavity. It also helps in shrinkage analysis. SDRC has also improved its cooling software with the ability to evaluate the thermal effects of inserts and slides.

The I-DEAS material database has been enhanced to include many additional properties required for the new simulation capabilities, and the total number of resins has been increased and grouped into 18 type classifications, which are further subdivided for various grades and filler content. (CIRCLE 95)