DE102018218260A1 - Structure with adaptive stiffening elements - Google Patents

Abstract

In a structure with vertical and horizontal structure elements for a building, oblique stiffening elements for horizontal stiffening of the structure are clamped between several of the vertical structure elements. At least one actuator is integrated in each of these oblique stiffening elements. These active stiffening elements allow the prestress to be adjusted at short notice for any period of time according to the respective requirements. The tensile and / or compressive stress of the respective stiffening element can thus be changed directly. Swinging of the structure due to dynamic forces can thus be counteracted directly, so that the stress peaks in the stiffening elements and other structure elements are lower. As a result, the structural and stiffening elements no longer have to be oversized and material and weight savings are achieved.

Description

Technical application area

The present invention relates to a structure with vertical and horizontal structure elements for a building, in which oblique stiffening elements for horizontal stiffening of the structure are clamped between several of the vertical structure elements.

Structures are used to transfer the static and dynamic loads of a building. The static part is based on the dead weight and the payload and interference loads, which are assumed to be constant or only slowly changing during the day. Dynamic loads result from the interaction with the surroundings of the structure or structure, such as, for example, when winds suddenly arise or changing wind speeds or during earthquakes.

The design of conventional structures with purely passive structure and reinforcement elements is based on the critical load case or the critical load case combination and the resulting maximum stresses on the support structure. However, this occurs extremely rarely or never within the life cycle of a building. The structure is therefore usually largely oversized.

Structures with a half-timbered construction have horizontal and vertical structural elements, oblique stiffening elements being braced between the vertical structural elements, also referred to as supports. The stiffening elements dissipate (dynamic) transverse forces and, thanks to the stiffening, ensure that the structural segments are minimized. As a rule, slack tensile elements such as ropes or flat steel are used as stiffening elements, which are usually prestressed once when the structure is erected to prevent buckling when compressive forces occur. The prestressing, however, requires a correspondingly higher dimensioning of the cross sections in the stiffening elements and the rest of the supporting structure. In fact, however, a correspondingly high preload is only necessary at times of a correspondingly high dynamic load.

State of the art

For earthquake protection of buildings, the use of active elements is known, which are used in addition to the passive supporting elements of the structure. These active elements are used in particular to dampen vibrations.

A basic distinction can be made between passive systems, active systems, semi-active systems and hybrid systems. Passive systems with purely passive structural elements do not require an external energy supply. Evoked reactions are caused by building movements. Examples include the energy dissipation with vibration absorbers or dampers as well as the shape adaptation to u. a. realizing an orientation according to the wind direction. Active systems react to external influences in order to influence or optimize the behavior of the structure, such as deformations, vibration properties or the internal flow of forces. In order to be able to apply the necessary forces, travel ranges, etc., external energy sources are required for active systems. Semi-active systems have the ability to adapt system properties such as rigidity or damping and, despite their high performance, do not require high-performance, external energy sources. Examples of such a system are dampers with controllable electro- or magnetorheological fluid. Hybrid systems are based on the combination of passive, active or semi-active systems.

From the US 9,896,836 B1 a structure is known in which a semi-active rotary band brake is used for vibration damping. This band brake is anchored to the floor slab or a floor of the building and dampens the deflection of a stiffening element that runs diagonally between vertical structural elements. In addition, a passive damping element in the form of a hydraulic lifting piston can also be integrated into this stiffening element. With such a system, however, the use of materials for a structure cannot be reduced. This solution also requires appropriate space for the arrangement of the band brakes.

The object of the present invention is to provide a supporting structure with vertical and horizontal supporting and inclined stiffening elements for buildings, which enables material and weight to be saved for the supporting structure.

Presentation of the invention

The object is achieved with the structure and the stiffening element according to claims 1 and 6. Advantageous configurations of the structure and the stiffening element are the subject of the dependent claims or can be found in the following description and the exemplary embodiments.

The proposed structure has several vertical and horizontal structure elements as well as inclined stiffening elements between several of the vertical structural elements. The structure elements represent the load-bearing elements of the structure. The oblique stiffening elements are braced between the vertical structure elements and serve to horizontally stiffen the structure, which can be a truss in particular. The inclined stiffening elements are each clamped between adjacent vertical structural elements, wherein the stiffening elements can be clamped between all vertical structural elements or only between a part of these structural elements. Furthermore, stiffening elements can also be braced between horizontal structural elements. The stiffening elements can be designed to be slack, for example in the form of ropes or flat steels, or also to be stiff in compression, for example in the form of corresponding kink-resistant profiles, and preferably run diagonally between adjacent vertical structural elements. The proposed structure is characterized in that at least one actuator is integrated into one or more of the obliquely extending stiffening elements or between one or more of the obliquely extending stiffening elements and a supporting structure element, via which the tensile or compressive stress or prestressing of the respective stiffening element, if necessary using a suitable mechanism. The actuators are force or length manipulable actuators.

In the proposed structure, some or all of the stiffening elements braced between vertical support elements are thus equipped with an integrated actuator system, via which a tensile and / or compressive stress or prestressing of the stiffening elements can be actively changed. Through this integration of at least one actuator in the respective stiffening element or the incorporation of the actuators between the stiffening element and the surrounding structure, and thus in the flow of force through this stiffening element, the prestress can be adapted at short notice for any period of time according to the respective requirements. This means that the load transfer behavior of the entire structure can also be changed for static loads. The proposed adaptive structure can actively influence the load transfer or the proportion of load transfer of a support element.

In connection with additional sensors on the structure or the structure and / or stiffening elements, the load transfer can be optimized using real-time control so that the structure components are stressed as evenly as possible and the stress curves within the structure cross sections are as homogeneous as possible. At the same time, the vibration amplitudes that occur can be reduced or damped. This results in better material utilization and it is possible to realize structural components with less material and less weight. The structural elements only have to be used for permanent loads, e.g. the dead weight of the structure, which allows considerable weight savings.

The proposed stiffening element for a supporting structure accordingly has at least one actuator which is integrated into the stiffening element or is fastened to it so that it can actively change the stresses in the stiffening element by appropriate control when the stiffening element is clamped between two supporting elements of a supporting structure. The stiffening element can be designed to be slack or rigid.

In the proposed structure or stiffening element, the actuators do not have to be continuously supplied with energy, but only when dynamic or additional static loads occur, for example loads that are caused by interaction with the environment, in particular by winds or also by earthquakes, snow load or payload surrender. By absorbing such dynamic or additional static loads through the proposed stiffening elements with integrated actuators, the cross section of the other structural elements of the structure can be reduced and thus material and weight can be saved.

The active control or regulation of the respective actuators takes place via suitable sensors on the structure or on the structure, for example via expansion and / or acceleration sensors, and a corresponding control or regulation algorithm of a control or regulation unit. The actuators can work according to different principles, as long as they can carry out the changes in the tension of the stiffening element required for the respective structure. Examples of suitable actuators are hydraulic or pneumatic cylinders, linear direct drives and piezo actuators. With appropriate mechanics, electrically, pneumatically or hydraulically driven rotary drives are also conceivable. The proposed structure is particularly suitable for high-rise buildings, bridges or similar structures in which the present invention enables a high saving in material. Of course, the proposed structure can also be used for other types of structures if required.

Figure list

• 1 einen allgemeinen Aufbau eines Tragwerksegments in Fachwerkbauweise gemäß dem Stand der Technik und dessen Verrautung beim Auftreten äußerer dynamischer Querkräfte;
• 2 eine Darstellung des Funktionsprinzips eines Tragwerks mit aktiven Aussteifungselementen gemäß der vorliegenden Erfindung;
• 3 eine Darstellung eines schematischen Kraftverlaufs von statischen und dynamischen Kräften eines drucksteifen Aussteifungselements mit und ohne Zuschalten des Aktors;
• 4 ein erstes Beispiel einer in das Aussteifungselement gemäß der vorliegenden Erfindung integrierten Aktorik; und
• 5 ein zweites Beispiel einer in das Aussteifungselement gemäß der vorliegenden Erfindung integrierten Aktorik.

The proposed structure and a stiffening element according to the invention used therein are explained in more detail below using exemplary embodiments in conjunction with the drawings. Here show:

• 1 a general structure of a truss structure in the framework of the prior art and its marriage when external dynamic transverse forces occur;
• 2nd a representation of the principle of operation of a structure with active stiffening elements according to the present invention;
• 3rd a representation of a schematic force profile of static and dynamic forces of a pressure-resistant stiffening element with and without switching on the actuator;
• 4th a first example of an actuator integrated in the stiffening element according to the present invention; and
• 5 a second example of an actuator integrated in the stiffening element according to the present invention.

Ways of Carrying Out the Invention

In the proposed structure, at least some of the bracing elements that run obliquely between vertical supporting elements are equipped with an actuator system that can actively influence a tensile and / or compressive or prestressing of the respective bracing element. In the following examples, the structure is designed as a framework. Such truss structures are usually made of columns as vertical structural elements 1 , horizontal structural elements running between the supports 2nd and stiffening elements 3rd built up like this in 1 is shown schematically using a structural segment of such a structure. The stiffening elements 3rd conduct dynamic lateral forces 8th and ensure through the stiffening that a roughening of the individual structural segments is minimized. In 1 In the left part, a supporting structure segment without stiffening elements can be seen. When lateral forces occur 8th As indicated by the arrows, this structural segment is to be avoided. By using appropriate stiffening elements 3rd between the vertical structural elements 1 such a bridle is exposed to transverse forces 8th prevented or at least significantly reduced, as in the right part of the 1 is indicated.

The stiffening elements 3rd and also the structural elements 1 , 2nd However, it must be set to the appropriate loads when the structure is erected. In particular, there must be a sufficiently high preload in the stiffening elements 3rd will be realized. However, this preload ensures a correspondingly higher dimensioning of the cross sections in the stiffening elements and the structural elements.

In the structure proposed according to the invention, stiffening elements with integrated actuators are used, by means of which the prestressing or the tensile and / or compressive stress in the stiffening elements can be changed or adapted to the respective load, if necessary. Swinging of the structure due to dynamic forces can thus be counteracted directly, so that the stress peaks in the stiffening elements and other structure elements are lower. As a result, a higher dimensioning of the stiffening and structural elements with correspondingly higher cross sections is no longer necessary, so that overall material and weight are saved. With the integration of the at least one actuator into a stiffening element or through the series connection of actuator and stiffening element, the load transfer or the proportion of the load transfer of the stiffening element can be actively influenced. 2nd illustrates the functional principle of a structure equipped with such active or adaptive stiffening elements using the visualization of the structure in the inactive, strongly vibrating state (left part of the figure) and in the active state with damped vibration (right part of the figure). The actuators 4th of the stiffening elements 3rd are only indicated in the right part of the figure. By influencing the tension with the actuators 4th In the right part of the figure, the forces acting can be absorbed, thus preventing the supporting structure segment from roughening, even with correspondingly weaker stiffening elements.

In 3rd are the static and dynamic forces acting on the stiffening element for a passive (not regulated) and active (regulated) stiffening element 3rd plotted over time, which oscillate sinusoidally around the static pressure load. While the static forces, which include not only the weight of the structure or structure, but also the prestressing of the element (in 3rd not shown for the sake of simplicity), cannot be changed over time, vibrations of the structure lead to dynamic forces that change over time. The vibrations result, for example, from gusts of wind. In 3rd the actuator is switched on from time t = 2 seconds. The diagram illustrates compared to the passive, non-regulated system, the lower loads. The determined by the regulation and by the actuator 4th applied forces are added to the existing element forces. If the actuators are switched on at the time of swinging up, the sum of element and actuator forces is permanently minimized and the dimensioning of the components, ie the structural elements and stiffening elements, leads accordingly to smaller component cross-sections.

This in 3rd stiffening element shown 3rd is not assumed to be slack and therefore also derives compressive forces. If the stiffening element in a construction consists of ropes or the like, it can be assumed that the opposite stiffening element transmits twice the tensile force of a construction consisting of compression-resistant diagonals. In the right part of the 3rd are the individual forces, ie external interference 8th , Element forces 9 and actuator forces 10th , shown on a corresponding structural segment with arrows.

The active stiffening element in the slack variant consists of tension elements, such as ropes or flat steels, which are used to connect to other structural elements. The tension elements 5 are in the example of 4th via two connection plates 6 connected to the actuators. Exemplary implementation principles, such as how tension or compression actuators can be integrated into a stiffening element, are in the 4th and 5 shown.

The structure of the actuator system can be designed, for example, in the following way. Tie rod 7 connect the connection plates 6 . With the help of the tie rods 7 a static prestress can also be introduced into the stiffening element by adjusting its length accordingly. The actuator 4a , 4b is between the connection plates 6 built in and generates a force that over the sub-bases 6 on the tension elements 5 pulls. This tractive force results either directly from the built-in traction actuator 4a - as in the design of the 4th - Or indirectly from a pressure actuator, in which the force generated is redirected with an auxiliary construction. Such a combination of pressure actuator 4b and mechanical auxiliary construction is in 5 shown as an example. Is the pulling force through the actuator 4a , 4b larger than the preload force, the connection plates move 6 towards each other.

A pressure-resistant variant can be implemented in the same way. However, the tension elements are for this 5 to be replaced by kink-resistant profiles that generally require larger component cross-sections.

With the proposed active stiffening element, the rigidity of a structure can be actively and directly influenced. By influencing the load transfer, the cross section of the load-bearing components can be significantly reduced, thus saving resources and gray energy. The vibrations within a support structure can be actively damped, thus extending the life of the components. A building with an adaptive support structure according to the present invention can adapt optimally to changing (load) conditions. The initial prestressing of the stiffening elements can be chosen to be very low and set directly in the actuator assembly. This only needs to be increased with the help of the actuators if dynamic loads require it. The module also enables the application of a static (minimum) preload in the event of an actuator failure etc.

Reference list

1

Vertical support element

2nd

Horizontal support element

3rd

Stiffening element

4th

Actuator

4a

Train actuator

4b

Pressure actuator

5

Tension element

6

Sub-base

7

Tie rod

8th

Cross or interference force

9

Element power

10th

Actuator force

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 9896836 B1 [0007]

Claims (7)

Support structure with vertical and horizontal support elements (1, 2) for a building, in which oblique stiffening elements (3) for horizontal support of the support structure are braced between several of the vertical support elements (1), characterized in that at least one actuator (4 , 4a, 4b) is integrated in one or more of the inclined stiffening elements (3) or between one or more of the inclined stiffening elements (3) and a supporting element (1, 2), via which a tensile stress and / or compressive stress of the respective stiffening element (3) can be changed. Structure after Claim 1 , characterized in that the stiffening elements (3) are formed slack. Structure after Claim 1 , characterized in that the stiffening elements (3) are pressure-resistant. Structure according to one of the Claims 1 to 3rd , characterized in that a plurality of sensors are arranged on the structure, via which movements and / or changes in length on the structure or one or more structure and / or stiffening elements (1, 2, 3) can be detected, the sensors being controlled by a control and / or a control unit are connected, by means of which the actuators (4, 4a, 4b) are controlled as a function of movements and / or changes in length detected by the sensors, in order to counteract the detected movements and / or changes in length at least when predetermined threshold values are exceeded. Structure according to one of the Claims 1 to 4th , characterized in that the stiffening elements (3) run diagonally between the vertical and / or horizontal support elements (1, 2). Bracing element for a supporting structure according to one or more of the preceding claims, in which at least one actuator (4, 4a, 4b) is integrated, via which, when the bracing element (3) is clamped in between two vertical supporting elements (1), tensile stress of the bracing element (3) can be changed. Stiffening element after Claim 6 , characterized in that the stiffening element (3) has two tension elements (5) which are attached to two connection elements, in particular connection plates (6), between which the actuator (4, 4a, 4b) acts.

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