Cadalyst Labs Review: NX 5, Part 21 Dec, 2007 By: Jeffrey Rowe Cadalyst
Enhancements in software architecture enable major improvements in assemblies, visualization, and drawings.
With more than 400 enhancements, there is no doubt that NX 5 is a major release for Siemens PLM Software (formerly UGS). In fact, it was so major that Cadalyst chose to split the review into two parts.
In Part 1 last month, I covered some of the basic aspects of NX 5 with regard to what makes this release so significant, getting started with sketching and part modeling, as well as using collaborative design practices. In Part 2, I'll cover assemblies, visualization, and drawings. Even though I was given the opportunity to review NX 5 in two parts, its many enhancements make it difficult to cover much beyond the highlights of this release.
Siemens NX 5
So, let's get started with assemblies and move on other significant aspects of NX 5.
For many MCAD packages, large-assembly (thousands of parts) performance is what separates the men from the boys. NX 5's significant architectural enhancements are the basis for major improvements in large-assembly modeling. To further improve assembly performance, the Siemens JT data format was integrated into NX 5. JT simplifies the pervasive multi-CAD environment that most manufacturers now deal with and offers lightweight assembly design functions for faceted assembly representations that improve performance when precise solid geometry isn't required, such as in design reviews (figure 1). To a large extent, it is the JT format that improves NX 5's large-assembly capacity and performance while reducing memory usage and rendering time. Siemens PLM Software claims that test cases with NX 5 have demonstrated at least a 60% reduction in memory usage and at least a 65% increase in display-frame rates for typical large assemblies. All in all, these represent pretty significant performance gains.
Figure 1. NX 5 introduces major architectural changes that dramatically improve design functions and performance for large assemblies. NX assembly modeling uses Siemens PLM Software s JT data format and Direct Modeling technology for lightweight, high-performance visualization and multi-CAD collaboration.
In NX 5, assembly part files point to geometry and features in the subordinate parts, rather than creating duplicate copies of those objects at each level in the assembly. This technique not only minimizes the size of assembly parts files but also provides high levels of associativity. This enables users to modify the geometry of one component so that all assemblies that use the same component automatically reflect the change. These relationships affect assemblies and other associated objects such as drawings, tool paths, and CAE meshes.
It's common practice in assemblies for a particular part to be used in many places. Each usage is referred to as an instance, and the file containing the actual geometry for the component is called the component part. For example, a car assembly may have two axle subassemblies, each of which has two wheel parts. In this example, we have four wheel instances and two axle subassembly instances but only two component parts (one wheel and one axle).
There are several approaches to assembly modeling, and with NX designers aren't limited to any one style. They can create individual part models and then later add them to assemblies (bottom-up), or they can create parts directly at the assembly level (top-down assembly creation). Additionally, users can start by using a top-down method and then switch back and forth between bottom-up and top-down modeling, depending on their specific needs. This versatile approach helps NX fit into a wide variety of workflows.
To expedite assembly design, multiple parts can be loaded simultaneously. Load options in the NX Assembly Navigator load implicitly or explicitly as a result of being used by some other loaded subassembly. The Assembly Navigator also lets users display information and manipulate the assembly for selecting, hiding, or suppressing assembly components. Additionally, loaded parts don't have to belong to the same assembly. The part currently displayed in the graphics window is called the displayed part. You can make edits in parallel to several parts by switching the displayed part back and forth between those parts.
Digital Prototyping and Visualization
The digital mockup (DMU) capabilities embedded in NX 5 are inherited from Teamcenter Visualization and are useful for design and review processes (figure 2). The big advantage is that overhead for data management is eliminated because only one file is required for this process, not the typical two — one for design and one for mockup purposes. DMU is a technology also frequently called digital, or virtual, prototyping. This technology allows users to design and configure complex products and validate their designs, theoretically eliminating the need to build a physical model.
Figure 2. NX 5 embeds Teamcenter engineering process management to support faster searching of managed data and to promote reuse. The integration also delivers efficiency gains for typical design tasks.
NX 5 has a capability called Active Mockup, an active technology that unites the ability to visualize an assembly mockup with the ability to measure, analyze, simulate, design, and redesign it (figure 3). Active Mockup lets users create a multi-CAD digital mockup and then visualize and modify it. This capability gives immediate feedback in the context of the assembly. Lightweight 3D models with multiple levels of detail using lightweight data structures, such as JT, let you visualize, analyze, and interact directly with product design data.
Figure 3. NX 5 Active Mockup supports true design in context, even for massive, multi-CAD assembly models. It improves large assembly performance and unites the review and redesign processes. This image depicts a dynamic cross-section of a tractor assembly model.
Drawings and 3D Annotation
Although the dream of the paperless office has been proposed for many years, it still proves elusive, and the fact remains that drawings aren't going away anytime soon. Drawings are created in NX's drafting environment, and NX 5 provides easy-to-navigate user interface (UI) elements for producing engineering drawings directly from 3D models or assembly parts, as well as from 2D parts. The drawings are associative to models, meaning that a drawing reflects changes in a model as a design progresses. This ability ensures that drawings are current with regard to assembly models or individual modeling piece parts. Although these capabilities aren't new or unique, they do make NX 5 easier to use.
The drafting environment includes drag-and-drop annotation, the ability to edit annotation values, and the ability to delete drafting objects; helper lines (dotted lines) that visually assist you in aligning annotations and drawing views; and the ability to select member views directly on a drawing and to move and align a view. Drafting options are accessible from Edit and Insert Menus, toolbars, and Resource tabs. You can also drag and drop template files from Resource bar options to automatically create parts lists, tabular notes, and drawings.
NX 5 lets you create 3D annotations, also known as product and manufacturing information (PMI), for capturing design intent, encouraging information reuse, and automating drawing creation (figure 4). New inheritance methods let you specify which PMI annotations will be inherited on 2D drawing views, eliminating the need to duplicate this step when creating drawings.
Figure 4. NX 5 lets users create 3D annotations such as PMI for capturing complete design intent, enabling information reuse, and further automating the drawing creation process.
The Associated Objects option in the drafting environment associates geometry to a PMI annotation. Designers can use this option to capture design intent by specifying the portions of the model to which the PMI pertains. For example, if you have a note that specifies a particular finish for several faces but you only want the note to point to one of the faces, you can attach the note to that face and use the Associated Objects option to associate all the faces to the note. If you select the note, then all its associated faces highlight in the graphics window.
Some Final Thoughts
By itself, NX 5 is a very capable MCAD application. The universal and more specialized improvements make NX 5 a very significant release. Although the core NX 5 package is very comprehensive, myriad optional modules are available for NX 5 for just about any aspect of CAD, CAM, or CAE. Although virtually no one could use them all, I can't really think of any design and design-related task that couldn't be performed using them.
NX 5 is a heavy-duty MCAD package that can do some pretty heavy lifting. By that I mean that it can handle just about all manner of mechanical and mechatronic design. It's also a package that users are very unlikely to outgrow. In fact, with additional modules, it can grow with users if their needs and requirements become more demanding and sophisticated.
I have to admit that with the new UI and the sequence of the workflow, I felt like I was doing more than just modeling parts and assemblies — I was designing them. Overall, I was pleasantly surprised at how relatively painless the learning curve was, thanks largely to the more contemporary UI that is much more Windows compliant.
NX 5 is a broad application that spans the large space from design to production. The company put a lot of time and effort in filling this space, and it shows.
This is the first major release of NX since UGS was acquired by Siemens. Admittedly, virtually all of the functionality for NX 5 was decided and developed before the acquisition was completed. How much direction and influence Siemens will have in the future is unknown, but NX 5 is certainly an MCAD candidate worthy of serious consideration.
Jeffrey Rowe is an independent mechanical design and technical communications consultant. With offices in Colorado and Michigan, he can be reached at 719.539.8549 or firstname.lastname@example.org.
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