Design Analysis

By Author: peter
Total Articles: 191

The design analysis routines available in a CAD system help to consolidate the design process into a more logical work pattern. Rather than having a back-and-forth exchange between design and analysis groups, the same person can perform the analysis while remaining at a CAD workstation. This helps to improve the concentration of designers, since they are interacting with their designs in a real-time sense. Because of this analysis, capability designs can be created which are closer to optimum. There is a time saving to be derived from the computerized analysis routines, both in designer time and in elapsed time. These saving results from the rapid response of the design analysis and from the time no longer lost while the design finds its way from the designer's drawing board to the design analyst's queue and back again.

An example of the success of this is drawn from the experience of the General Electric Company with the T700 engine. In designing a jet engine, weight is an important design consideration. During the design of the engine, weights of each component for each design alternative must be determined. This had in the past been done manually Patek Philippe Replica by dividing each part into simple geometrical shapes to conveniently compute the volumes and weights. Through the use of CAD and its mass properties analysis function, the mass properties were obtained in 25% of the time formerly taken.

Since alterations in preliminary designs are generally easier to make and analyze with a CAD graphics system, more design alternatives can be explored and compared in the available development time. Consequently, it is reasonable to believe that a better design will result from the computer-aided design procedure.

Interactive CAD systems provide an intrinsic capability for avoiding design, drafting and documentation errors. Data entry, transposition, and extension errors that occur quite naturally during manual data compilation for preparation of a bill of materials are virtually eliminated. One key reason for such accuracy is simply that no manual handling of information is required once the initial drawing has been developed. Errors are further avoided because interactive CAD systems perform time-consuming repetitive duties such as multiple symbol placement, and sorts by area and by like item, at high speeds with consistent and accurate results. Still more errors can be avoided because a CAD system, with its interactive capabilities, can be programmed to question input that may be erroneous. For example, the system might question a tolerance of 0. 0001 mm. It is likely that the user specified too many zeros. The success of this checking would depend on the ability of the CAD system designers to determine what input is likely to be incorrect and hence, what to question.

There is also a high level of dimensional control, far beyond the levels of accuracy attainable manually. Mathematical accuracy is often to 14 significant decimal places. The accuracy delivered by interactive CAD systems in three-dimensional curved space designs is so far beyond that provided by manual calculation methods that there is no real comparison. Computer-based accuracy pays off in many ways. Parts are labeled by Breitling Replica Watches the same recognizable nomenclature and number throughout all drawings. In some CAD systems, a change entered on a single item can appear throughout the entire documentation package, effecting the change on all drawings which utilize that part. The accuracy also shows up in the form of more accurate material and cost estimates and tighter procurement scheduling. These items are especially important in such cases as ling-lead-time material purchases.

The single data base and operating system is common to all works-stations in the CAD system. Consequently, the system provides a natural standard for design/drafting procedures. With interactive computer-aided design, drawings are "standardized" as they are drawn; there is no confusion as to proper procedures because the entire format is "built into" the system program.