When considering the many challenges of designing structural steel superstructures, from high-rise complexes to sprawling single level industrial facilities to open-air (column free) arenas, one fact has remained consistent (even in today’s high-tech realm of computer-aided design and drafting (CADD)) – a huge amount of structural steel design and fabrication documentation is required to move the project successfully from engineering to design layout to detail drafting to fabrication shop drawings and finally, field erection.
Every steel pile, girder, beam, column, joist, truss, plate, channel, tube, and bar must go through a multitude of raw material transformations – cut, punched, formed, machined, bending, finished, welded, drilled, bolted or riveted to precise specifications for assembly by third-party metal fabricators. To reach a successful construction phase, each piece will be piece marked and tracked in multi-level advanced bill-of-materials and erection sequencing diagrams.
The point being made is, with such a massive design documentation feat – how can a 3D structural steel model-centric approach help A&E firms better manage the engineering workflow and enhance the three challenges to designing steel superstructures – cost, speed, and quality (according to AISC.org – Steel Framed Office Buildings – Meeting The Challenges Of The 21st Century).
What is Model-Driven Fabrication
While 3D structural steel models are commonplace for almost all large-scale A&E projects and are used quite effectively for 3D visualizations and animations, conceptual design presentations, multiple level BIM projects, and engineering analysis and calculations – many of these same firms will use a secondary approach to steel detailing, assemblies, and shop drawings. The traditional 2D or orthographic layout, annotation and dimensioning of the numerous diagrams required for fabrication and erection is cumbersome, redundant, and mistake-prone.
Many firms use outsourced engineering services to generate fabrication or shop drawing documentation, a preferred method with high-quality results compared to leaving this task to the fabricators. Partnering with a service that understands the machine shop flow, is committed to your project schedule, and uses an information-rich, model-driven approach to streamline fabrication drawing productivity will greatly enhance project costs, speed, and quality.
Model-driven fabrication takes advantage of the entire 3D model from beginning to end of the design construction process, removing drafting bottlenecks and productivity redundancy to produce accurate and detailed material schedules, estimation take-offs, detailed layouts, assembly and sub-assembly BOMs, and fabrication drawings. The key element in the model-driven fabrication workflow is producing a fabrication-ready model in the engineering design phase.
Start With a Data-Rich 3D Structural Steel Model
The Engineering Design staff prides itself on creating information-rich, fabrication-ready 3D structural steel models which present a high-level of detail and contain additional data for fast and accurate fabrication drawing production.
- a single database supports complex projects with file sharing and edit permission protections, allowing multiple designers to work on the same model for increased efficiency
- segregated model construction using layered and stylized graphics for easy viewing and information separation
- real 3D-axis, solids and surfaces to support automatic cross-sections, elevations, orthographic, and isometric view generation
- automatic generation of shop drawings by simply isolating views, manipulating layers, and adding additional shop annotation
- accurate real-time information availability for project managers or shop floor operations, such as material specifications and grade, material supplier information, or crosslinks to detailed assembly drawings and piece mark information
- model-wide clash detection for accurate coordination of all structural steel components to prevent field construction setbacks and protect profit margins
- automatic updating of change information for each steel component, wherever the component exists on any drawing in the project file
- drafting and detailing productivity support with a complete library of industry-standard details, connections, and commonly used components from bolts to beam profiles
Fabrication Solutions with Tekla Steel Structural Models
Developers of the Tekla Steel software application recognized and responded to fabrication challenges in structural steel superstructure design. Increased flexibility and powerful productivity tools support steel detailing and assembly drawing processes. The result is minimized steel fabrication rework – an issue which promotes costly field delays, engineering change notifications, or less than optimum on-site welding and punching operations as quick fixes.
The company deliberately built-in software enhancements strategically aimed at creating detailed 3D models that are fabrication-ready. Detailing efforts are maximized and mistakes are minimized by removing drafting redundancies. Every detailed 2D drawing is a manipulated view of the single 3D structural model; a model which can incorporate CNC machining processes, robotic welding parameters, or important material handling information.
Coordination and communication between engineering and construction can also be accomplished through the 3D model’s project file. Imagine field change requests happening in real-time, with engineers able to review and analyze the request, provide engineering approval, and automatically update all affected components and assemblies – in one day.
Tekla offers an Open AP programming interface for seamless data transfer between vendor and/or fabricator software through standard file formats including IFC, DXF, DWG, and DSTV-NC. A Tekla Structure model can be utilized for engineering analysis, as well as detailing, estimation, fabrication, and erection – and the software offers mobile solutions for portability.
In-Model Shop Drawing Engineering Review and Approval
A recent Structure Magazine online article took the 3D structural steel model-driven fabrication workflow one step further – important for those firms that already use outsourced engineering services to construct and populate information-rich, fabrication-ready models. That is, using a 3D Tekla Structures model as a means for in-model engineering review and approval of the steel shop drawings, to make sure the fabrication information corresponds to the intended design parameters.
A proprietary application used the Tekla Open Application Programing Interface (API) to develop custom dialogue boxes to present pertinent fabrication information. In an instant, all structural components of the submittal package are color coded to represent the current submittal status of each piece mark. For instance, different colors of the model will represent a submittal component that is without issue or if a submittal component has fabricator comments attached and requires engineering attention.
“After selecting an individual main member and viewing the basic information through the approval dialogue window, Tekla Structures automatically generates additional views with detailed information on the connections such as the quantity, size, spacing and type of bolts, size and type of welds, and connection plate grades and dimensions.”
“All information needed for review was quickly available to the reviewer through dialog boxes and views generated automatically through Tekla Structures. All miscellaneous pieces, such as connection plates and stiffeners, are associated with the members they attach to, so all pieces are reviewed through viewing the main members.”
From here the engineering approval process is applied as the engineer responds with the traditional ‘Approved As Noted’ or ‘Revise and Resubmit’ response. The visual cue makes it easy to track the shop drawing review progress and makes it less likely to miss fabricator comments. This takes the traditional shop drawing submittal and review process from a static and cumbersome process, to one that is dynamic and responsive.
If you are faced with a large-scale steel superstructure project that requires substantial manpower or the experience and skill to create fabrication-ready 3D structural steel models, consider offshore engineering services that have been successful at leveraging top talent at a lower cost.
Multiple contract arrangement models are typically offered, from complete project-based services using top flight and highly requested CADD software packages or tasking certain portions of the project to augment in-house staff.