WO2012117273A1 - Parametric truss and roof modelling system, and method of its use - Google Patents

Abstract

The goal of this invention is a parametric interactive system for modelling/design of truss lattice member 3D models (1). The exclusive feature of this invention is that such modelling system provides a single parametric 3D model of a truss lattice member that is adapted to the interactive CAD environment and is common to all types of truss lattice member groups. Configuration of each 3D model assumes the required geometric shape depending on the overall truss design and on the preset conditions. Moreover, the said 3D models automatically adjust to the changes of truss geometry and assume required shapes, when truss geometric parameters and truss configuration are modified. Such system ensures fast, error-free, and effective truss design/modelling process. Such system enables fast and error-free correction and improvement of existing designs. When connected to the adequate (appropriate) mechanical equipment, this interactive system (medium) enables production of all said truss lattice members from corresponding material that later could be used for assembly of the truss (on construction site/ground).

Description

PARAMETRIC TRUSS AND ROOF MODELLING SYSTEM, AND METHOD OF ITS USETechnical Field

This invention is related to roof modelling systems, especially to parametric systems of truss and roof modelling, allowing professionals of respective fields to design and model various complex truss and roof structures.

Background Art

Construction is one of the oldest fields of human activity, and roofs are the most expensive and important parts of buildings, protecting the interior of the house from precipitation and other natural elements, and creating required microclimate therein. The roof type is selected depending on the type of the building, terrain, and environmental conditions from a vast variety that is available today globally. External conditions are not fully predictable, therefore constructing a firm and durable building roof is a difficult task, solving of which involves participation of large groups of professionals, especially today, when building designs are not only complex, but exotic as well. Different systems for modelling of roofs/trusses, interactive media packages and software packages are being developed to facilitate work of engineers and designers: from simple calculators for calculations of basic roof and truss parameters to complex interactive parametric media for professionals of the respective fields.

There are known an American patent Nr. WO9816080, published on October 18, 2005, which describes a system for monitoring pillar loads, adapted for mines and underground structures. The load level is determined by a programmable micro-controller that is embedded into the said supporting structure and connected to the pressure sensors. This system could also be applied to hydraulic jacking systems and building roofs. The roof loads could be judged by the numeric signal supplied by the micro-controller or by the colour of corresponding live LEDs. However, the system only measures loads of existing roofs/supports and does not provide any tools for simulation/design of roofs/trusses in some functional interactive medium.

The known British patent No. GB2457215 (Korean: No. KR100545358B), published on August 12, 2009, describes an automated system for modelling of cities and roofs of buildings that is adapted for modelling of urban infrastructure while taking into account the local terrain. However, the system is optimized for developing an overall image of urban roofs (from above) and is not intended for simulation of particular buildings or their roofs.

Another known British patent is No. GB2406180 (Japanese: No.JP8022479), published on March 23, 2005, describes a system operating in a computerized medium for creation of 3D models that subsequently can be used for building design. The users are provided with an interactive medium with the following customizable input parameters: terrain, building block, walls, roof, etc. With these virtual instruments/tools, users are able to model a whole building from the foundation up to the roof in a particular environment. However, this interactive medium is not parametric and is more adapted for designers, since objects created with the tool perform as many functions as the user assigns in case for each particular element. That makes it complicated and awkward.

The known American patent No. US2010241403, published on September 23, 2010, describes an interactive medium, consisting of a multitude of construction elements and including building construction and deconstruction stages. Utilising these construction elements, a user is able to develop a structure of a building or a building complex. An exclusive feature of this patent is the ability of the said interactive medium to aggregate in memory the complete sequence of user actions and suggest the most optimal erection sequence of the said building according to the deconstruction sequence the structure. However, the system does not provide any tools for construction of roofs or trusses.

By the technical level the closest patent is the Australian patent No. AU2010201839, published on April 16, 1998. It describes a system for construction/modelling of building roofs in interactive medium. Utilising various essential roof elements, the users are able to design unique and specifically fitted roofs. They can form personal libraries of more complex elements or use libraries created by other users. However, the system suffers from the same handicap: objects created with the tool perform have as many functions as the user assigns in case for each particular element.

As described above, we see that the interactive media described in patent literature provide users with tools, including a range of various roof/truss elements enabling them to construct building roofs or corresponding trusses. Yet the number of roof and truss designs is so great that even very competent professional users find it difficult to quickly construct one or another truss for a particular roof type or even a particular roof utilizing the said tool set. On the other hand, if a user needs to improve/modify a specific truss part, he will have to remodel all interconnected truss parts. When the truss assembly to be improved / to be modified belongs to a bigger structure, the whole modelling process becomes very (extremely) complicated.

Technical Problem

Technical Solution

SUMMARY OF THE INVENTION

According to the geometric shape, trusses can be divided into two main types: parallel chord trusses and pitched trusses. If truss structure consists of both pitched and parallel chord trusses, such trusses are called mixed or truncated trusses. Taking into account roof geometry and truss support points, trusses can be divided into zones with truss lattice elements of similar geometric shape: posts and struts. The number and form of lattice members depends on the length of the said zone, external factors and structural requirements. Truss lattice elements are grouped according to types with standard conventional names, such as Fink, Howe, Pratt, etc. Analytically, truss zones can be divided into panels according to repetitive lattice member group types. Truss lattice members being the most difficult to geometrically model/select constitute the basis of all roof trusses. The reason thereof is a large number of member group (panel) types and a considerable geometric variety even in (within) the same truss. Moreover, one truss may include various panel types.

This invention seeks to create such parametric system/interactive medium for modelling of trusses and roofs that was not only capable of modelling all said members of truss lattice depending on truss configuration, but would also ensure that the said truss lattice members automatically could be adjusted to changes in the truss geometry, when modifying geometric parameters of the whole truss or the truss configuration. Such system would enable fast, error-free, and effective construction/modelling of trusses by professionals of the respective fields. Also, such system would enable fast and error-free correction and improvement of existing designs. Also, when connected to adequate mechanical equipment, this interactive system/medium would enable production of all said truss lattice members from corresponding material that later could be used for assembly of trusses.

The essence of this invention is the unified general parametric 3D model of truss lattice member that is suitable for all types of truss lattice member groups, is adapted for interactive CAD environment, and capable of automatically adjusting to changes of truss initial input parameters and truss geometry. 3D model configuration of the said truss lattice member depends on its location, the zone and the panel of the truss, the panel type, and the panel member type. Depending on the truss configuration, the said 3D model of the lattice member automatically acquires the required geometrical shape, i.e., it and its ends are automatically formed according to the preset conditions. The said preset conditions depend on the contacts of the said lattice member 3D model with the upper and lower truss chords, poles, struts, etc. Depending on the requirements, an acceptable tolerance may be defined (introduced) for the said lattice member 3D model - the distance of a section from a contact surface or an axis (in case of a perpendicular section).

The exclusive feature of this invention is that the provided parametric 3D model of a truss lattice member is common to all types of truss lattice member groups. Moreover, the said 3D models can be various and numerous depending on the geometry and input parameters of the modelled/selected trusses, i.e., the whole set of 3D models of the truss lattice members is generated automatically that adjusts not only to the initial input parameters and the selected truss geometry, but to changes of the geometry/parameters as well.

By utilizing such interactive medium and the said 3D model of truss lattice members this invention enables modelling/design of various truss models and sending (exporting) them into corresponding truss libraries for later use. Moreover, when connected to the adequate mechanical equipment, this interactive medium enables production of all truss lattice members for a roof.

Advantageous Effects

Description of Drawings

Fig. 1 illustrates a unified parametric 3D model (1) of truss lattice members that is suitable for all types of truss lattice member groups, is adapted for interactive CAD environment, and capable of automatically assuming the required shape in an interactive modelling system depending on truss configuration and initial input parameters.

Fig. 2 illustrates an example generated by the said truss lattice member 3D model (1) that is adjusted to the lower truss chord (2) and the adjacent lattice member (3).

Fig. 3 provides an example of a parametric truss structure, consisting of a set of the automatically generated 3D models (1) of the said members.

Best Mode

Designing of trusses for building roofs is an important task of global proportions, for quality and accuracy of truss structures determine strength and durability of building roofs. Vast variety of building types and their designs lead to the extensive range of truss designs. After emergence of computers, a multitude of interactive systems/media of different levels have been developed to facilitate the process of truss modelling and design enabling modelling of trusses for selected roof types. The systems of this type usually consist of a core modelling module that provides access to all tools of the interactive medium and of a library module storing and providing access to the already created objects/designs. However, the main handicap of such systems is that a user can use multitude of provided elements and tools for modelling of a truss. That leads to several problems at the same time. First, the mechanism (process) of truss construction/modelling is very complicated making it difficult even for very competent professional users to quickly construct one or another truss for a particular roof type. Secondly, if a user needs to improve/modify a single specific part of a truss, he will have to remodel the whole truss structure, which makes the modelling process extremely complicated, if the modified truss block is a part of a larger structure. And the last problem is the human factor: high complexity of truss structures increases the probability of an accidental error or discrepancy that may develop into a major problem on the construction site (ground).

The interactive system for design/modelling of trusses (lattice members) proposed by this invention ensures fast, error-free, and effective design/modelling of trusses. The system utilizes an innovative technical approach/solution wherein the multitude of structural elements (tools) is replaced by a single unified parametric 3D model of truss lattice member that is suitable for all types of truss lattice member groups, is adapted for interactive CAD environment, and that automatically assumes the required shape depending on the truss configuration and the initial input parameters, i.e., the model itself and its ends are automatically formed according to the preset conditions that depend on the contacts of the said lattice member with the upper and lower truss chords, poles, struts, etc.

Fig. 1 illustrates the preferred embodiment of the invention - a version of a parametric truss lattice member 3D model (1) that automatically assumes the required shape in the said interactive modelling system depending on truss configuration and initial input parameters. Moreover, depending on requirements, an acceptable tolerance may be defined (introduced) for the said lattice member 3D model - the distance of the section from a contact member or an axis (in case of a perpendicular section).

Such different truss lattice member 3D models (1) can be various and numerous depending on configuration of truss structure, and the said parametric truss modelling system automatically generates the complete set of the said 3D models (1). Additionally, a user is able not only quickly and error-free generate a corresponding set of 3D models (1) fitted for a particular truss design, he can also easily make improvements of the truss structure as a whole, i.e., the generated set of 3D models (1) responds not only to the initial truss configuration parameters, but to their modifications as well. By utilizing such interactive system/medium and the said 3D model of lattice members this invention enables quick and error-free modelling/design of various truss models and sending them into a corresponding truss library for storing. This interactive truss modelling system is particularly useful for designers who are prone to focus less on the correct technical solutions and more on the overall aesthetic view/design of roofs, since it requires less attention to the technical parameters of trusses.

Fig. 2 illustrates an example of truss lattice member 3D model (1) that is adjusted to the lower truss chord (2) and the adjacent lattice member (3).

By utilizing such modelling system / interactive medium and the said truss lattice member 3D model (1), this invention enables modelling/construction of various truss models and sending (exporting) them into corresponding truss libraries for later use. Many quality truss designs can be developed for different building roofs by following the concept of creation of truss lattice member 3D model (1). Fig. 3 provides an example of a (commonly used) parametric truss structure, consisting of a set of automatically generated 3D models (1) of the said members. In this design, the lower (2) and upper (4) truss chords can be classified as 3D model (1) members. Though truss designs are various and numerous, they all are based on the said general single parametric 3D model (1) of truss lattice members that is common to all types of truss lattice member groups.

Truss parameters and their geometry are closely linked to building roof parameters and their geometry. Roof geometry and support (joint) locations determine truss geometry, especially geometry of the upper chord, which affects the different truss parameters, such as altitudes, slopes and planar breaks. The said altitudes, slopes and planar breaks determine/affect the dimensions of truss zones. Roof sides and bridges (if supports are present) affect geometry of the lower chord: altitudes, slopes, planar breaks and zone dimensions. Geometry of roofs and supports influence the number of truss zones.

Designers (users) of the said truss design system define parameters of truss member sections and maximal panel lengths, select truss lattice types for zones, insert additional truss zones, if required, and correct altitudes of the lower chord. Additionally, users can select cornice carcass types and adjust truss console member parameters. All these truss parameters may be adjusted/ modified at any time during modelling/design. The values entered/adjusted by a user are sent into the parametric lattice member 3D model (1) whose geometry depends (completely) on these user parameters: truss slope parameters, zone upper altitude parameters, corresponding distance parameters of lattice members from upper and lower chords, truss member section parameters, zone lattice member types, geometric parameters of member ends and other related parameters. Then, an example of specific lattice member of member 3D model (1) is generated, depending on user input parameters and the location of member 3D model (1) in specific truss zone, panel, and panel grating. Member modelling is performed by means of parametric object 'Solid', and the ends thereof are modelled (i.e. ends trimmed) by means of parametric object 'Void' (in case of a wooden truss). In case of a metal truss, member trimming requires input of additional conditions and requirements, such as structural requirements for member distances to truss chords and other lattice members. If lattice members are to be welded, welding seem lengths and other related parameters need to be taken into account. In case of metal trusses, additional parts are used for joining of lattice members together and with the upper and lower chords by means of metal connecting plates. In such cases, the geometry of the connecting plates can be additionally modelled, taking into account all structural and strength requirements. In specific cases, axes of lattice members don't coincide with analytical (design) axes. Therefore member 3D model (1) is supplemented by the system of variable axes of truss members.

When connected to adequate mechanical equipment, this parametric interactive truss modelling system enables not only modelling, but even production of complete sets of truss lattice member 3D models (1) from corresponding materials, such as wood and/or metal.

The above descriptions of preferred embodiment scenarios are provided to illustrate and describe this invention. This is not an exhaustive or limited invention that seeks to establish an exact form or embodiment scenario. The above description should be treated as an illustration and not as limitation. Obviously, many modifications and variations can be evident for professionals of corresponding fields. The embodiment scenarios are selected and described to explain in the best possible manner to professionals of corresponding fields the principles of this invention and their best practical applications in various embodiment scenarios and variations adjusted for specific applications or implementations, since quantitative indicators of application of this method may differ in case of specific truss types or designs. All terms used in the scope of invention as defined by the claims and its equivalents are to be understood in the broadest meaning possible unless indicated otherwise. Modifications of embodiment variations described by professionals of corresponding fields should be acknowledged as remaining in the scope of this invention according to the following claims.

Mode for Invention

Industrial Applicability

Sequence List Text

Claims (8)

1. Parametric system for modelling of trusses and roofs, consisting of the core modelling module that provides tools of interactive medium and the library module that stores and gives access to already created objects/designs,characterized in that the core module is based on a single unified parametric 3D model (1) of truss lattice member that is suitable for all types of truss lattice member groups, is adapted for interactive CAD environment, and that automatically assumes the required geometric shape depending on the truss configuration, i.e., the model itself and its ends are automatically formed according to the preset input parameters and defined conditions that depend on the contacts of the said framework member with the upper and lower truss chords, poles, struts, etc., where:

   the said lattice member 3D model (1) performs the truss lattice function, and/or the truss upper chord (4) function, and/or truss lower chord (2) function;

   a designer defines truss input parameters, such as truss member section parameters, maximal panel dimensions, zones lattice member types, additional truss zones, lower zone altitudes, cornice carcass types, truss console member parameters, upper zone altitude parameters, corresponding distance parameters of lattice members from upper and lower chords, cut parameters of lattice member 3D model (1), etc.
2. Parametric system for modelling of trusses and roofs according to claim 1,characterized in that the tolerance is defined for the said parametric truss lattice member 3D model (1) depending on external conditions and requirements - distance of section from a contact member or an axis.
3. Parametric system for modelling of trusses and roofs according to claim 1 or 2,characterized in that depending on the modelled/selected truss geometry the said parametric truss lattice member 3D models (1) may be numerous and various, and comprise a set of the said 3D members (1) that is automatically generated by the said parametric system for modelling of trusses and roofs.
4. Parametric system for modelling of trusses and roofs according to claim 3,characterized in that the said set of lattice member 3D models (1) adjusts not only to the initial input parameters of truss configuration, i.e., to modelled/selected truss geometry, but to modifications of this geometry as well as designers/users adjust the said truss input parameters.
5. Parametric system for modelling of trusses and roofs according to any or some of the previous claims 1-4,characterized in that

   it models lattice member 3D models (1) from different materials, such as wood and/or metal;

   it takes into account welding seem lengths and other related parameters in case of welding of metal parts;

   it employs additional parts for joining of lattice members of metal trusses together and with the upper and lower chords by means of metal connecting plates;

   it models the shape/geometry of the said connecting plate.
6. Parametric system for modelling of trusses and roofs according to any or some of the previous claims 1-5,characterized in that

   the lattice member 3D model (1) is modelled by applying a system of variable axes of truss members in cases,

   when axes of lattice members don't coincide with analytical (design) axes.
7. Parametric system for modelling of trusses and roofs according to any or some of the previous claims 1-6,characterized in that it is connected to an adequate mechanical equipment module for production of the said designed lattice member 3D models (1) from corresponding material, such as wood and/or metal.
8. Method of use (application) of the parametric system for modelling of trusses and roofs that comprises (encompasses) application of the said core modelling module, the library module, and the mechanical equipment module,characterized in that this parametric system for modelling of trusses and roofs is according to any or some of the previous claims 1-7.

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