System for connecting a first component and a second component to form a flexurally rigid frame corner

Abstract

The invention relates to a system for connecting a first load-bearing component (1) to a second load-bearing component (2) in order to form a flexurally rigid frame corner, having a first connecting plate (12), which is arranged on the first component (1), and a second connecting plate (22), which is arranged on the second component (2), wherein a. the connecting plates (12, 22) each contain a first bore, in which a bolt element (3) is introduced in order to form a defined axis of rotation, b. the connecting plates (12, 22) contain further, mutually correspondingly arranged apertures (14, 24), in which is arranged at least one screw (4) which braces the connecting plates (12, 22) against one another, and c. the further apertures (14, 24) and the at least one screw (4) are dimensioned such that rotation is possible through a defined angle of rotation about the axis of rotation.

Description

The invention relates to a system for connecting a first component and a second component in order to form a flexurally rigid frame corner. The system is provided, in particular, for use on or in buildings, in particular buildings in earthquake regions.

DD 290 464 A5 relates to a mechanical damping element for vibration which occurs between a foundation and an object located thereon in regions which are vulnerable to earthquakes. The damping element has a baseplate on which steel balls which are arranged at the corner points of the object can move horizontally, the steel balls being enclosed, in the movement directions, by resilient material. The running-surface side of the steel balls is free of the elastic-plastic material.

DE 34 02 449 C2 relates to an apparatus for damping vibration on tower-like structures, having a pendulum, with a pendulum rod, which is suspended on a cantilever support of the structure, for executing three-dimensional vibration, under which the lower end penetrates loosely in an upwardly open cavity of a frictional weight. The frictional weight is made up of a plurality of non-connected circular-disk-form friction plates which are stacked one upon the other and of which the external diameter increases from the upper plate to the lower plate. The lowermost plate is mounted in a displaceable manner on a base, and the cavity is formed by central holes in the friction plates, wherein the hole diameter increases from the upper friction plate to the lower friction plate.

DE 43 05 132 C1 relates to a friction damper for securing load-bearing structures against dynamic effects, having at least two friction plates which are arranged one above the other, make contact along curved contact surfaces and are connected in alternating fashion to a first or second of two friction-damper connections. A pre-tensioning means for the friction plates arranged one above the other is provided.

DE 10 2007 051 285 A1 relates to a fastening bracket having a first and a second fastening limb, which are connected to one another via a deformation element, and therefore the first fastening limb can be displaced in relation to the second fastening limb with the deformation element being deformed in the process.

EP 1 170 429 A1 relates to a vibration-counteracting reinforcing holder having a base part which is formed by the two end parts of a plate being rotated and bent in one direction. Fastening pieces are thus formed on the reinforcing holder. Absorber parts, which have rubber elasticity and via which the base part is fixed on structural parts, are provided.

EP 1 164 225 A1 relates to a vibration-counteracting metal fitting, having an L-shaped base part which is formed by virtue of a plate being bent, and has bent and projecting parts, with inward bending in the intermediate regions of the two parts. A reinforcing part is formed by virtue of a plate being bent and is in contact with a bent part of the L-shaped base part. Absorption parts made of a rubber material are arranged at various locations of the L-shaped base part.

In frames with so-called flexurally rigid frame corners in the frame corners, all horizontal loads have to be absorbed and passed on. The connection between the so-called posts and crossmembers, on the one hand, therefore has to have a very high level of rigidity, so that wind alone does not cause the structure to vibrate excessively; on the other hand, the connection also has to allow deformation to the extent where, in the case of an earthquake, failure does not occur, that is to say the flexurally rigid frame corners do not collapse.

If use is made of flexurally rigid frame corners, these have the great advantage over stiffening plates that free and variable utilization of ground-plan space is made possible.

It is an object of the present invention to provide a system which makes it possible to provide, along with straightforward assembly, a high level of safety and effectiveness for structures.

This object is achieved according to the invention by a system having the features of the main claim. Advantageous configurations and developments of the invention are given in the dependent claims, the description and the figures.

The system according to the invention for connecting a first component and a second component in order to form a flexurally rigid frame corner, having a first connecting plate, which is arranged on the first component, and a second connecting plate, which is arranged on the second component, provides that the connecting plates each contain a first bore, in which a bolt element is introduced in order to form a defined axis of rotation, that the connecting plates contain further, correspondingly arranged apertures, in which is arranged at least one screw which braces the connecting plates against one another, and that the further apertures and the at least one screw are dimensioned such that rotation is possible through a defined angle of rotation about the axis of rotation.

Structural parts in buildings, such as posts and crossmembers, are often produced from wood or metal. Wood has an extremely high load-bearing capability in relation to its mass, and therefore load-bearing structures with a low dead weight are possible. This low dead weight is advantageous, in particular, when earthquakes cause the building to vibrate from the foundations. If structures are then designed with a very high level of rigidity, and the building also has a high mass, very high levels of stressing occur and, with the materials having a low dissipation potential, these often result in the structure failing. The dissipation potential in wooden structures, on account of the low level of plastic deformability, resides not as much in the wood itself as in the junction points, that is to say in the connections between the individual components. The invention provides that connecting plates are formed on the individual components, are configured preferably as steel plates and are arranged at the ends of the respective components, and that these connecting plates, in order to ensure precise positioning of the components in relation to one another and also a sufficient capability to transmit static loading, each contain a first bore, into which a matching bolt element is introduced. The bolt element serves for the secure and precise positioning of the connecting plates in relation to one another and, at the same time, as an axis of rotation, about which the components can pivot. The connecting plates contain further, or second, correspondingly arranged apertures, for example ones which have been milled out, punched out or the like, which in the assembled state, that is to say the state in which the two connecting plates butt against one another, cover over one another at least in part, and therefore at least one screw, via which the two connecting plates can be braced against one another, can be arranged through the two apertures or further apertures. Said second or further apertures here are dimensioned such that rotation is possible through a defined angle of rotation about the axis of rotation defined by the bolt element in the first bores. The connecting principle of the system is thus based, in the first instance, on a rotatable coupling between two components and the securing of the latter in relation to one another in the first instance via friction which is generated between the two connecting plates, preferably consisting of steel, by the pre-tensioned, preferably high-strength screws. The transmission of the forces and moments for the predominantly at-rest loads thus takes place, in the first instance, via the friction between the two connecting plates, wherein linear-elastic deformation is present in the event of an increase in forces or moments. Energy dissipation takes place within the components and the connecting plates; displacement of the connecting plates in relation to one another is not yet taking place. It is only when the loading reaches a high enough level that the static friction is exceeded that energy dissipation takes place by kinetic friction, in the case of which the connecting plates are rotated in relation to one another about the axis of rotation defined by the bolt element. The rotation here is defined only by the dimensions or shaping of the further apertures. The larger the aperture in comparison with the tensioning screws, the greater can the displacement be until the connecting plates and the tensioning screws come into direct contact with the peripheries of the further apertures. Up until this contact is made, the connection between the two components remains free of plastic material deformation or plastic damage. If the deformation continues to increase, bearing forces are activated in addition in order to maintain the connection; the bearing forces are absorbed by the bolt element and the tensioning screws in the respective apertures.

In order to make it possible for the connecting plates to be guided as precisely as possible relative to one another, the internal diameter of the first bores and the external diameter of the bolt element correspond to one another; the aim is a transition fit, a fit with a low level of play or a snug fit of the bolt element within the first apertures. The dimensions of the bolt element and of the first bores here should be selected such that the components can be assembled on site, that is to say on the construction site, and basic rotatability about the axis of rotation formed by the bolt element is possible. A low level of play, in line with the dimensions of the bores and of the bolt element, may be provided for this purpose; relevant lateral displacement in the plane of the connecting plates should not be possible. The level of play can be up to 1 mm in the case of large bolt and bore diameters. The first bore and the bolt element are advantageously round.

The internal diameters of the corresponding further apertures are advantageously larger than the external diameter of the screws which brace the connecting plates against one another, this allowing rotation of the connecting plates relative to one another when the static friction is exceeded. There is no need here for the internal diameter of the two further, or second, apertures to be larger than the external diameter of the screws; rather, it is also possible for one connecting plate to have a further aperture with an internal diameter corresponding to, or matching, the external diameter of the screw, whereas only the corresponding aperture in the second connecting plate is larger.

It is likewise possible for one or both further apertures to be configured as slots and have, for example, a curved shape which corresponds to the envisaged rotary path of the two components in relation to one another. It is thus possible to ensure a kind of guidance of the rotation of the two components by the tensioning screws. The dimensioning and/or shaping of the further apertures define the maximum angle of rotation of the two components in relation to one another until such time as material deformation occurs on account of the peripheries of the apertures being in direct contact with the screws. This defines the range and path of the kinetic friction between the connecting plates for energy dissipation.

The connecting plates are advantageously provided with a defined coefficient of friction, which is as constant as possible over the service life of the system, in order for it to be possible to define at the outset the frictional forces which occur following assembly. On the surfaces which are directed toward one another, the connecting plates may be roughened or provided with regular unevennesses, and this therefore realizes, in the assembled state, a defined coefficient of friction between the two surfaces located one upon the other. The aim is for the contact surfaces of the connecting plates to have a permanently defined coefficient of friction so that it is possible to realize a reliable design and a stable construction over the service life of the structure. The tensioning screws are preferably tightened with such a high torque that the static friction between the connecting plates is at a sufficiently high level to absorb the static and dynamic forces during conventional usage of a building. It is only under extremely high loading, for example in the event of storms or earthquakes, that the static-friction forces are exceeded. The material strength of the screws and of the bolt elements in relation to shearing forces here is greater than the static friction applied, and it is therefore possible to provide for a further safety reserve in the connection between the two components following the kinetic-friction phase.

A development of the invention provides for a sensor device for monitoring the compressive loading between the connecting plates, and therefore the pressure to which the contact surfaces of the connecting plates are subjected can be monitored on a permanent basis, and there is sufficient and defined static friction present between the connecting plates over the useful life of the connection.

The sensor devices may be designed as disks, for example as washers between the connecting plates or beneath the screws. It is also possible for a transmission element to be assigned to the sensor device or the disks, this element making it possible, without high-outlay equipment, to measure the compressive force between the connecting plates, the tightening of the screws being adjusted only in the case of this measured value falling below a limit value. The transmission can take place wirelessly, for example via a radio element or RFID transmission or via a cable or some other signal conductor. A transponder may be arranged in the sensor device, and this makes it possible, during and after the screw-connection of the connecting plates, on the one hand to achieve precisely defined pre-tensioning and, in addition, to be able to monitor, during usage of the connecting system, whether the pre-tensioning is still present.

The individual disks or sensor devices may be assigned markers, and it is therefore possible to determine precisely which screw connection has which torque and which static friction is realized at which location between the connecting plates.

It is possible, in principle, for a plurality of connecting plates to be arranged in alternating fashion one behind the other in the axial direction, in order to be able to absorb high loading.

Exemplary embodiments of the invention will be explained in more detail hereinbelow with reference to the accompanying figures, in which like reference numerals designate like components and:

FIG. 1 shows a schematic illustration of two components in plan view;

FIG. 2 shows a side view of FIG. 1;

FIG. 3 shows a plan view of the components according to FIG. 1 in the assembled state;

FIG. 4 shows a side view of FIG. 3;

FIGS. 5a-5d show illustrations of connecting plates on their own;

FIGS. 6a-6d show assembled components with connecting plates according to FIGS. 5a to 5d; and

FIG. 7 shows a schematic illustration of a moment/rotation diagram.

FIG. 1 illustrates a first component 1 made of a wooden beam 11 with a connecting plate 12 incorporated therein. The wooden beam 11 and the connecting plate 12 can be screwed to one another, and the connecting plate 12 consists preferably of a steel or some other high-strength material which can be connected to the beam 11. In order to connect the connecting plate 12 to the wooden beam 11, a slit is preferably made in the wooden beam 11, the connecting plate 12 being pushed into said slit; the connecting plate 12 is fixed, and connected permanently, to the beam 11 via conventional dowel rods, possibly in conjunction with adhesives or other fastening elements. Corresponding fastening takes place on a second component 2, which likewise has a wooden beam 21 with a second connecting plate 22 fastened therein or thereon. Instead of a wooden beam, the posts and crossmembers used may also be made of other materials, for example metal, plastics, concrete or the like. Fastening of the connecting plates 12, 22 on the respective load-bearing members 11, 21 takes place in accordance with the materials and the appropriate connecting methods. It is also possible, in principle, for a plurality of connecting plates 12, 22 to be arranged on the respective load-bearing members 11, 21; it is also possible for a plurality of connecting plates 12, 22 to be arranged one behind the other, wherein the spacings between the connecting plates 12, 22 arranged one behind the other are dimensioned such that a corresponding connecting plate of the other component can be arranged between two connecting plates.

In the exemplary embodiment illustrated, the first connecting plate 11 has formed in it a first bore 13, which is positioned centrally between two first apertures 14. The first bore 13 has a diameter which is smaller than the diameter of the circular apertures 14.

A corresponding first bore 23 and correspondingly arranged second or further apertures 24 are arranged in the second connecting plate 22.

FIG. 2 shows that the two connecting plates 12, 22 project beyond the respective load-bearing member 11, 21, and therefore the connecting plates 12, 22, for assembly purposes, can be positioned congruently one above the other. The second connecting plate 22 here is larger than the first connecting plate 12, which has its end side projecting beyond the longitudinal extent of the first load-bearing member 11.

FIG. 3 illustrates the two components 1, 2 in the assembled state. It can be seen from FIG. 3 that, in the assembled state, the two first bores 13, 23 are aligned with one another. A bolt element 3, of which the external diameter essentially corresponds to the internal diameter of the two bores 13, 23 is guided through the bores 13, 23, wherein the dimensions are selected such that the connecting plates can be assembled, rotated and simultaneously precisely positioned in relation to one another. A defined axis of rotation for the two connecting plates 12, 22, and thus also for the two components 1, 2, relative to one another is thus formed around the bolt element 3.

Tensioning screws 4 are guided through the two further apertures 24, arranged alongside the respectively first bores 13, 23, in order to brace the connecting plates 12, 22 against one another. FIG. 4 shows the assembled state with the screw 4 guided through. The external diameter of the screw 4 here is smaller than the internal diameter of the apertures 14, 24, and therefore, once the static friction has been exceeded, with a moment applied about the axis of rotation of the bolt element 3, it is possible for the two components 1, 2 to be displaced in relation to one another.

A sensor device 5 for determining the compressive force is arranged beneath the head of the screw 4, and possibly beneath the nut, and therefore the force by which the two connecting plates 12, 22 are braced against one another can be monitored on a permanent basis.

Those surfaces of the connecting plates 12, 22 which are in contact are provided with a surface which has a defined coefficient of friction. This can be achieved by a particular coating or shaping of the surface, for example by surface treatment by way of forming or cutting, for example by machining. The surfaces of the connecting plates 12, 22 may be provided with regular unevennesses, in order to be able to achieve defined coefficients of friction. It is likewise possible for the surface to be configured such that, as the angle of rotation about the axis of rotation, which coincides with the center axis of the bolt element 3, the coefficient of friction increases, and this therefore means that, under low-level loading, the two components 1, 2 can rotate in relation to one another, once a limit loading has been exceeded, until the static friction retains the two components 1, 2 in position; as loading increases beyond the limit value, the moment of resistance increases, and it is only when maximum deflection beyond the kinetic-friction range has been reached that there is material deformation occurring in the region of the screws 4 and of the bolt element 3.

In the exemplary embodiment illustrated, the sensor elements 5 are designed as washers beneath the screw head and the nut of the tensioning screws 4 and may be provided with a transponder or some other transmission device, thus allowing wireless monitoring of the compressive force applied at the respective screw-connection location; it is also possible, in principle, for the disks to be arranged between the connecting plates 12, 22. Should the compressive force decrease over time, or be reduced as a result of shocks or subsidence, the tensioning screw 4 can be pre-tensioned further in order for the desired pressure of the contact surfaces of the connecting plates 12, 22 against one another to be maintained in a defined manner on a permanent basis.

The geometry of the connection of the two components 1, 2 via the connecting plates 12, 22 with the bores 13, 23 with identical internal diameters and the matching diameter for the bolt element 3 makes it possible for the system to allow deformation without the components undergoing plastic deformation. This deformation within the connection does not lead to failure of the flexurally rigid frame corner formed by the two components 1, 2 being connected to one another. The first bores 13, 23 define the axis of rotation and the position of the components 1, 2 in relation to one another; the further apertures 14, 24 allow displacement about the axis of rotation and bracing of the connecting plates 12, 22 toward one another via tensioning screws 4, and it is therefore possible to achieve reliable connection of the components 1, 2 under normal loading, whereas, in the event of earthquakes, the components can be displaced relative to one another about the axis of rotation without the connection collapsing.

FIGS. 5a to 5d show different connecting plates 12, 22, only those parts of the connecting plates 12, 22 which project out of the load-bearing members 11, 21 being illustrated. The connecting plate 12 of the first component 1, alongside the bore 13, has two round apertures 14 with a diameter which is larger than that of the bore 13; the second connecting plate 23 has a first bore 23 with a diameter which is identical to the diameter of the first bore 13 of the first connecting plate 12; the two further apertures 24 are designed as slots, wherein the central aperture 24 is shorter than the left-hand aperture 24.

In FIG. 5b, the bores 13, 23 and apertures 14, 24 are formed in their symmetry to the arrangement according to FIG. 5a, and therefore the correspondingly formed bores 13, 23 are arranged at the left-hand end of the row of apertures 14.

In FIG. 5c, the bore 13 is arranged centrally between apertures 14, 24, which are arranged symmetrically in relation to the bore, the apertures 14 of the first connecting plate 12 are configured as circular bores, and the apertures 24 of the second connecting plate are configured as equal-length slots.

The embodiment of FIG. 5d corresponds to that of FIG. 5c, the apertures 24 of the second connecting plate 22 being designed as circular apertures with a size corresponding to the aperture sizes in the first connecting plate 13.

FIGS. 6a to 6d illustrate the different possibilities for displacement of the components 1, 2, wherein the configuration of the connecting plates 12, 22 corresponds to the configuration in the equivalently numbered image of FIG. 5.

It can be seen in FIG. 6a that, starting from the basic position, in which the load-bearing members 11, of the components 1, 2 are perpendicular to one another, pivoting can take place relatively far upward, since the left-hand aperture 24, in the form of a slot, allows correspondingly extensive displacement of the second component 2 in the upward direction. FIG. 6b shows the possible displacement in the correspondingly other direction.

In FIG. 6c, symmetrical displacement can take place over a relatively wide range since the bore 13, 23 is arranged centrally between the slots 24, and in the center of the longitudinal extent, and therefore the components 1, 2 can be pivoted uniformly in a defined angle range about the axis of rotation, which is located in the center of the bores 13, 23.

In FIG. 6d, the symmetrical configuration of the round apertures 14, 24 and the central arrangement of the bores 13, 23 likewise allow symmetrical displacement about the starting position, albeit to a lesser extent than in FIG. 6c.

FIG. 7 illustrates a diagram which shows the transmittable moment plotted in relation to the rotation α. In a first phase I, the connection between the two components 1, 2 is linear-elastically rigid until the static friction has been exceeded. This is followed, in phase II, by a pronounced kinetic-friction region, which runs more or less linearly. With the coefficient of friction graduated over the angle of rotation α, it is possible for phase II to contain an increase, which may be linear, progressive or degressive. At the end of the kinetic-friction phase II, the rotation about the axis of rotation of the bores is pronounced enough for the tensioning screws to come into contact with the peripheries of the apertures 14, 24 and therefore, following rotation about the angles of rotation defined by the shape and dimensioning of the apertures, bearing forces are activated, and these then, in turn, result, following initially elastic rotation, in the material of the bolt elements 3 and screws 4, in particular steel, starting to creep, which ultimately results in the screws 4, and possibly the bolt elements 3, breaking. The breaking point of the screws 4 here is lower than the strength of the material of the load-bearing members; the breaking strength of the bolt elements 3 may be higher than that of the screws 4, and therefore, once the screws 4 have broken, further deformation of the structure and of the frame corner is possible, so that further energy dissipation can take place without the structural integrity being lost.

Claims

1. System for connecting a first load-bearing component (1) to a second load-bearing component (2) in order to form a flexurally rigid frame corner, having a first connecting plate (12), which is arranged on the first component (1), and a second connecting plate (22), which is arranged on the second component (2), wherein

a. the connecting plates (12, 22) each contain a first bore, in which a bolt element (3) is introduced in order to form a defined axis of rotation,

b. the connecting plates (12, 22) contain further, mutually correspondingly arranged apertures (14, 24), in which is arranged at least one screw (4) which braces the connecting plates (12, 22) against one another, and

c. the further apertures (14, 24) and the at least one screw (4) are dimensioned such that rotation is possible through a defined angle of rotation about the axis of rotation.

2. System according to claim 1, characterized in that the internal diameter of the first bore (13, 23) and the external diameter of the bolt element (3) correspond to one another.

3. System according to claim 1, characterized in that, in the case of the correspondingly arranged apertures (14, 24), the internal diameter of the further aperture is larger than the external diameter of the screws (4).

4. System according to claim 1, characterized in that the further apertures (14, 24) are designed as slots.

5. System according to claim 1, characterized in that, on the surfaces which are directed toward one another in the assembled state, the connecting plates (12, 22) have a defined coefficient of friction.

6. System according to claim 5, characterized in that, on the surfaces which are directed toward one another in the assembled state, the connecting plates (12, 22) are roughened or are provided with regular unevennesses.

7. System according to claim 1, characterized by the provision of a sensor device (5) for monitoring the compressive forces between the connecting plates (12, 22).

8. System according to claim 6, characterized in that the sensor device (5) is designed with a wireless transmission device.

9. System according to claim 1, characterized in that a plurality of connecting plates (12, 22) are arranged in alternating fashion one behind the other in the axial direction of the bolt element (3).

10. System according to claim 1, characterized in that the connecting plates (12, 22) are non-planar.