WHFF Project: 2017.06
Project manager: Andreas Müller
The main points in brief
The research project investigates the technical possibilities for refurbishing wood components and joints through digital recording, CAD processing and machine production, which means understanding wood joints through reverse engineering.
The market offers a variety of measurement techniques for digital building recording. It can be stated that a suitable technique is available for every measurement task.
There are numerous exportable interfaces for measuring devices. In most cases, the ".las" format has proven itself for the import of point clouds.
In the case of existing timber structures, in addition to the structural and static requirements, there are often issues relating to the preservation of historical monuments that must be taken into account when planning the refurbishment.
Software and recording devices are continuously evolving, leading to increasingly precise, efficient and cost-effective digital building recording.
Project description
The aim of the research project was to record the current state of the art with regard to digital building recording and to apply it by means of 1:1 experiments. CAD-supported renovation planning should provide support and cost savings in the planning process. Finally, possibilities and limits of digital building recording as well as the planning and production chain of historic timber components were shown in a practical way.In order to facilitate solution finding, CAD-supported rehabilitation planning for reinforcement measures on common solid wood joints and connections was demonstrated. The extent to which a continuous digital chain is possible in this context was also investigated. In order to achieve the set objectives, the current state of the art with regard to digital construction recording was first investigated and presented. Subsequently, the requirements for the level of detail of the recording as well as the technical feasibility with commercially available equipment were examined in more detail. In parallel, a renovation variant was developed for a recorded historic solid timber connection, namely a lockbau corner connection (Gwätt).
Conclusions
The market offers a wide range of measurement techniques for digital building recording. It can be stated that a suitable technique is available for every measuring task.
High-quality stationary scanners and hand-held scanners with target guidance are very suitable for recording wood joints. If accessibility is good and only a few measuring surfaces are available, the use of a swivel arm with probe can be useful. For larger areas and uneven surfaces, a swivel arm with scanner is also recommended.There are a variety of exportable interfaces for measuring devices. In most cases, the ".las" format has proven itself for importing point clouds.
For marking a building and linking it to project data, the use of a QR code is recommended. This can be applied as a sticker or plaque.In addition to the structural and static requirements, existing wooden structures often raise monument preservation issues that must be taken into account in the renovation planning.When working on the renovation model of the Wallis log wall, it became apparent that the process from scan data processing to the construction of the renovation component is time-consuming, despite current technologies and software. The scan data is extensive and requires powerful software for processing. Using the "Cadwork" software system, it was possible to transfer the designed component to the software for NC machining.
Outlook: Devices for capturing part geometries are evolving very rapidly in terms of accuracy, ease of use, and measurement and processing speed. At the same time, new smartphone generations already offer various options for capturing linear dimensions and point clouds. Significant advances in recording devices are expected to be made in the near future.
Here you can download the full final report:
You can find more information about the project on ARAMIS.
The project was supported by the Swiss Forest and Wood Research Funding Switzerland (FOWO-CH) of the Federal Office for the Environment (FOEN) and the Conference for Forests, Wildlife and Landscape of the cantons.