EP1507050A1 - Force transfer element - Google Patents

Abstract

The compound material strip (5) is pretensioned by the power flow element (1) and in the transition from this element to the compound material there is a extension element (4) or similar to prevent additional tension peaks when the strip is stressed beyond the pretensioning load. This extension element is connected mechanically or through adhesive to the compound material strip. Independent claim describes method for increasing tensile load of compound material strip by connecting tension-blocking element.

Description

Technical area

The invention is based on a force introduction element for Anchoring a band-shaped composite material to a support structure according to the preamble of the first claim.

The invention also relates to a method for increasing the tensile load a band-shaped composite material and the use of a Force introduction element for reinforcing a support structure.

State of the art

For the subsequent reinforcing of supporting structures are for some Years in addition to steel blades and laminations made of composite materials used. These composites will either be limp without Longitudinal bias or biased via end anchors with the Bonded support structure. Such end anchors are known and various attachment methods for power transmission of a Force introduction element to the composite material are already in the market introduced. Most of the force discharges available today are the transferable forces but less than the tensile strength of the composite, which has the disadvantage that the tensile potential of the composite only to can be exploited to a limited extent, resulting in uneconomical Solutions leads.

Most of the previously used force injections are the tensile forces occurring during pretensioning via frictional forces due to clamping or bonding a force introduction element to the composite material transfer. The main problem with the force discharges available today is that stress peaks at the transition from the composite in the force introduction element arise. The maximum transferable tensile load is but then reached when the thrust in the voltage peaks the maximum transferable stiction, or the maximum transferable adhesive strength reached. Experience has shown that even with carefully executed Force introductions described, for example, in WO 99/10613 A1 and WO 96/21785, the maximum transferable tensile load only about 70 to 75% of maximum tensile load of the composite achieved. That's why such force discharges with observance of a safety factor of 1.5 only to about 50% of the maximum tensile load of the composite claimed become.

Presentation of the invention

It is therefore an object of the present invention to eliminate the disadvantages of existing prior art overcome and funds available provide an increase in the maximum transferable tensile load.

This object is achieved by means of an inventive Force introduction element according to claim 1 solved.

The solution to the problem is that after the clamping process of the band-shaped composite material in the pulling direction in a second step a means for preventing additional stress build-up at Transition from the cross-traverse to the force introduction element is used.

In the first step, the composite is over the The force application element and the transverse crosshead are tensioned onto the preload load. This creates voltage spikes at the transition of the cross-beam to Force application element. After preloading and anchoring on Bauwerk will use a compound with the composite material in a stretched state an adhesive or mechanically bonded. The connection between the Means and the composite material is free of tension at this time. at an additional load of the composite, e.g. from operating loads, become the resulting additional stresses mainly on the upstream means directly into a supporting structure and not or only slightly in the Transmitted force introduction element. This results in an increase in the Total load while maintaining the required safety factor.

The force introduction element may be referred to as a clamping head be and can be configured essentially as desired. For example consists of this force introduction element of two pressure plates and at least one tension member passed through the composite, e.g. Bolt. Or the composite material is using two pressure plates with the help of uniformly distributed printing elements or by means of one on the entire Anpressfläche acting hydraulic pressure chamber against a bow-shaped yoke held supported. Or instead of bolts and plates are used clamping wedges, the elliptical ring hoop to the Composite material to be pressed.

The advantages of the invention are that the inventive solution used for each existing on the market force application element can be. This means of reducing stress peaks at the transition from the cross-beam to the force introduction element can Extension element to the composite material and tensile to the Transverse cross member mechanically anchored and / or glued. Or the cross-beam is in the second step by injecting an adhesive connected to the composite material. Increased by this tensioning process the maximum transferable operating forces in compliance with a Safety factor of 1.5 at least 20-50% in a range of 300 up to 400 kN.

Further advantageous embodiments of the invention will become apparent the dependent claims.

Short description of the drawing

In the following, embodiments will be described with reference to the drawings the invention explained in more detail. Same elements are in the different Figures provided with the same reference numerals.

Fig. 1:

Eine schematische Seitenansicht einer ersten Ausführungsform;

Fig. 1a:

Eine schematische Draufsicht der ersten Ausführungsform;

Fig. 1b:

Eine schematische Seitenansicht der ersten Ausführungsform in einer leicht abgewandelten Ausführung;

Fig. 2:

Eine Seitenansicht einer zweiten Ausführungsform;

Fig. 2a:

Eine Draufsicht der zweiten Ausführungsform;

Fig. 3:

Eine Seitenansicht einer dritten Ausführungsform;

Fig. 3a:

Eine Draufsicht der dritten Ausführungsform;

Fig. 4:

Eine Draufsicht einer vierten Ausführungsform;

Fig. 4a:

Eine Seitenansicht der vierten Ausführungsform mit einer keilförmigen Verklebung des Verlängerungselementes an den Verbundwerkstoff;

Fig.4b:

Eine Seitenansicht der vierten Ausführungsform mit einer zickzackförmigen Verklebung des Verlängerungselementes an den Verbundwerkstoff;

Fig. 4c:

Eine Seitenansicht der vierten Ausführungsform mit einer wellenförmigen Verklebung des Verlängerungselementes an den Verbundwerkstoff.

Show it:

Fig. 1:

A schematic side view of a first embodiment;

Fig. 1a:

A schematic plan view of the first embodiment;

Fig. 1b:

A schematic side view of the first embodiment in a slightly modified embodiment;

Fig. 2:

A side view of a second embodiment;

Fig. 2a:

A plan view of the second embodiment;

3:

A side view of a third embodiment;

Fig. 3a:

A plan view of the third embodiment;

4:

A plan view of a fourth embodiment;

Fig. 4a:

A side view of the fourth embodiment with a wedge-shaped bonding of the extension element to the composite material;

4b:

A side view of the fourth embodiment with a zigzag adhesive bonding of the extension element to the composite material;

4c:

A side view of the fourth embodiment with a wave-like bonding of the extension element to the composite material.

Way to carry out the invention

In Figures 1, 1 a, 1 b and 2, 2a and 3, 3a and 4, 4a, 4b, 4c are represents four embodiments.

In Figures 1 and 1a is a force introduction element 1 after a Clamping process shown. The clamping process can first with a pull press take place, which is temporarily arranged on the force introduction element 1. Thereon is the tensile load of the composite material 5 from a cross-Traverse. 2 accepted. Threaded rods 9 are laterally on the force introduction element. 1 mounted, these threaded rods 9 through the cross-beam 2 of the Force introduction element 1 lead. The force application element 1 is about the cross-beam 2 and the threaded rod 9 in a not shown Anchoring tube or shear pin held in a well in a Support structure 10 is attached. By turning a threaded screw 8 of Threaded rod 9, the tension of the composite material 5 can be increased.

Adhesive 6 becomes after the clamping process of the force introduction element 1 in the pulling direction 11 in a second step on and in front of the transverse cross member 2 opposite the force introduction element 1 on the band-shaped Composite 5 applied. The adhesive is especially pasty to the To facilitate processing. An extension element 4 is placed on the on the band-shaped composite material 5 lying adhesive compound 6 launched and on glued the cross-Traverse 2 of the force application element 1 and preferably mechanically by lateral sliding of the Extension element 4 anchored in the cross-beam 2. For this purpose, the Cross-traverse clamp-like extensions on.

The extension element 4 must be resistant to tension with the transverse crossbeam. 2 be connected. The shape of the extension element 4 depends on the Choice of material of the extension element 4 and the thickness of Composite 5 and is chosen, inter alia, that the Extension element 4 to the composite material 5 back from the cross-beam Tapered away.

The extension element 4 can take any shape, but preferably have a tongue or wedge-shaped configuration to optimally reduce the voltage peaks. Also, in the Extension element 4 in the pulling direction 11 a few centimeters long ribs and folds 13 are introduced to allow for optimal bonding and to ensure optimum stress relief. The extension element 4 preferably has a length, respectively on the top and bottom of the band-shaped composite material 5, of 100 mm, in particular 50 mm. In the center of the extension element, this preferably has a thickness of a maximum of 10 mm, in particular a maximum of 5 mm. The Extension element 4 and the cross-beam 2 is preferably made metallic, ductile materials, in particular of aluminum, steel or Titanium.

The adhesive 6, e.g. a 2K adhesive based on epoxy resins, must a good adhesion not only to the composite material 5, but also to the Extension element 4 have and should have a high strength.

The stresses occurring during this clamping process are in the Voltage diagram 12 shown schematically, where x along the way of the force introduction element 1 and y represents the force at location x. Because the Cross-Traverse 2 is not bonded to the composite material 5, are the Voltage peaks at the transition from the cross-beam 2 to Force introduction element 1 highest and decrease towards zero to for the end of the pressure plates 3 of the cross-Traverse 2 averted Force introduction element 1. By attaching the Extension element 4 will be additional voltage spikes at the place of Cross-Traverse 2 and the force application element 1 largely prevented. As a result, the transferable force increases in compliance with the Fuse factor of 1.5 up to 20 - 50% compared to one Force introduction element 1, in which a cross-Traverse 2 frontally arranged the pressure plates 3 and no extension element 4 is used becomes. The available tensile load of the composite material 5 can be utilized to a greater extent and an expected tensile force of 300 to 400 kN can be achieved.

The composite material 5 can be configured in the form of a lamella, which consists of fibers and a synthetic resin. The fiber can be in one Direction i. be formed unidirectionally or additionally fibers in others Directions, in particular an angle plus 45 ° and minus 45 °, to be constructed unidirectional main fiber direction. The fibers can preferably of aramid, carbon, glass, etc., which are in a synthetic resin are embedded. The synthetic resin may be a duromer such as e.g. Epoxy, acrylates or a thermoplastic material, such as e.g. Polyamide, epoxy, acrylates. For the achievement of an optimal adhesion to the pressure plate 3 is the Surface of the composite 5, preferably specially embossed, e.g. roughened by grinding or pretreated with an adhesive or with a pretreatment system, e.g. Treated primer, plasma, etc.

Figure 1 b shows the force introduction system 1, in which before the Clamping process a bond 6 between the cross-beam 2 and the Composite material 5 executed and after the clamping process the Extension element 4 is attached. This results in the area of the cross-beam 2 shows a different voltage curve 12 than that in FIG. 1 shown so that the highest voltage peaks already in the range of Cross traverse occur.

Figures 2 and 2a show that after the clamping process of a Force introduction element 1 in the pulling direction 11 in a second step the Cross-Traverse 2 by injecting an adhesive 6 with the Composite 5 is connected. Since the cross-Traverse 2 in a second Step is glued to the composite material 5, the voltage spikes both at the location of the cross-beam 2 and the composite material 5 as well as on Location of the transverse cross member 2 and the force application element 1 highest and decrease in the pulling direction 11.

Shown in FIGS. 3 and 3a, the extension element 4 lying on the adhesive compound 6 on the band-shaped composite material 5 placed and glued to the cross-beam 2 of the force application element 1 and fixed with at least one screw 7. This points to that Extension element 4 an extension with holes through which the Guided screws and can be connected to the cross-beam.

In the embodiment shown in Figures 4, 4a, 4b and 4c is the extension element 4 on the lower side to the composite material. 5 specially shaped to a good bond and thus a high To ensure tension in the pulling direction 11. The Extension element 4 is also here on the adhesive 6, which on the band-shaped composite material 5 was applied, laid on and also adhered to the cross-beam 2 of the force introduction element 1.

The lower side of the extension element 4 to the composite material 5 is, for example, according to FIG. 4a wedge-shaped, according to FIG. 4b zigzag or according to Fig. 4c wavy. In the field of rejuvenation must due to the small thickness of the extension element if necessary, to dispense with a special shape. These above described shapes can also in the cross-Traverse. 2 be applied.

Of course, the invention is not limited to those shown and limited embodiments described.

LIST OF REFERENCE NUMBERS

1

Force application element

2

Cross-Traverse

3

pressure plate

4

extension element

5

Band-shaped composite material

6

adhesive

7

screw

8th

screw

9

threaded rod

10

supporting structure

11

tensile direction

12

voltage diagram

13

ribs

Claims (11)

Force introduction element (1) for anchoring a band-shaped composite material (5) to a support structure (10), wherein the composite material (5) is prestressed by means of the force introduction element (1), characterized in that in the transition region from the force introduction element (1) to the composite material (5) a means (2, 4, 6) is connected to the composite material (5) for the purpose of preventing additional stress peaks under stresses of the composite material (5) above the prestressing load. A force introduction element (1) according to claim 1, characterized in that the means is an extension element (4) and is connected to the composite material (5) mechanically and / or with an adhesive (6). Force introduction element (1) according to claim 2, characterized in that the extension element (4) is frontally connected to a transverse cross member (2) of the force introduction element (1) mechanically and / or with an adhesive (6). Force introduction element (1) according to one of claims 2 or 3, characterized in that the extension element (4) preferably has a hyperbolic, tongue or wedge-shaped form and preferably tapers towards the composite material (5) in the direction of the center of the composite material (5) , Force introduction element (1) according to one of claims 2 to 4, characterized in that the extension element (4) consists of a ductile material, preferably of aluminum, steel or titanium. Force introduction element (1) according to claim 1, characterized in that the means is an adhesive (6) which connects a transverse cross member (2) of the force introduction element (1) with the composite material (5). Force introduction element (1) according to one of claims 1 to 6, characterized in that the composite material (5) opposite side of the means (2, 4) has an enlarged and structured surface and is preferably designed wedge, zigzag or wavy. A method for increasing the tensile load of a band-shaped composite material (5), wherein the band-shaped composite material (5) by means of a force introduction element (1) is biased, characterized in that after the clamping process in the transition region from the force introduction element (1) to the band-shaped composite material (5) means (2, 4, 6) is connected to the composite material (5) above the preload load to prevent additional stress peaks on stresses of the composite (5). A method according to claim 8, characterized in that the means is an extension element (4) and is connected to the composite material (5) mechanically and / or with an adhesive (6). A method according to claim 8, characterized in that the means is an adhesive (6) which is introduced into a space between a cross-beam (2) of the force introduction element (1) and the composite material and the cross-beam (2) with the Composite material (5) connects. Use of a force introduction element (1) according to claims 1 to 7 for reinforcing a support structure (10), in particular a Concrete structure.

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