WO1998009032A1

WO1998009032A1 - Method for producing a doubly curved structural part from profiled sheets, and structural part

Info

Publication number: WO1998009032A1
Application number: PCT/NL1997/000485
Authority: WO
Inventors: Johannes Wilhelmus Marcus
Original assignee: Hoogovens Staal B.V.
Priority date: 1996-08-27
Filing date: 1997-08-27
Publication date: 1998-03-05
Also published as: AU4034297A; NL1003884C2

Abstract

Method for producing a doubly curved shell-like structural part, for example a so-called hyparshell roof, by joining at least two profiled sheets each having an imaginary axis of greatest flexural stiffness in the neutral plane of the profiled sheet to one another with their axes of greatest flexural stiffness essentially in one plane at an angle α differing from 0° after they have been twisted around an axis of lower flexural stiffness.

Description

METHOD FOR PRODUCING A DOUBLY CURVED STRUCTURAL PART FROM PROFILED SHEETS AND STRUCTURAL PART

TECHNICAL FIELD

The invention relates to a method for producing a doubly curved structural part from profiled sheets and also to a doubly curved structural part, for example hyperbolically paraboloidal structural part, made of profiled sheets.

DISCUSSION OF THE PRIOR ART A hyperbolically paraboloidal structure of flat sheets or sheet parts extending essentially in one plane has been disclosed (see for example US-3 , 206 , 895 , US- 3,727,356 or US-3 , 186 , 128) .

DESCRIPTION OF THE INVENTION According to the invention an improved doubly curved structural part is possible if it is essentially assembled from profiled sheets.

For this purpose, at least two profiled sheets each having an imaginary axis of greatest flexural stiffness in the neutral plane of the profiled sheet are joined to one another with their respective axes of greatest flexural stiffness essentially in one plane at an angle a differing from 0° after they have been twisted to some extent around an axis of lower flexural stiffness.

Within the scope of this application, a profiled sheet must be understood as meaning a nonflat sheet which has a profile in which valleys and ridges are situated with their longitudinal edges alongside one another, for example as is the case in the profiled sheet generally described as corrugated sheet. In this connection, this may also refer, for example, to a profiled sheet having a trapezoidal profile or a crenellated or a triangular or even a dovetail -type profile. Moreover, it should be understood as a profiled sheet which, as a result of its shape or structure, has a high or a low flexural stiffness, respectively, in two directions in the plane of the profiled sheet. By assembling such profiled sheets in this way, a structural part is obtained which is sufficiently stiff in all directions and can be assembled from in principle only two types of components, namely profiled sheets and joining components for joining them to one another.

To assemble a structural part, for example a roof or a wall, the profiled sheets do not need any particular pretreatment . The structural part or the roof or the wall does not need to be provided at its edges with stiff edge beams. Furthermore, the fitting of a rail system is superfluous and a support can be of light design. For a high flexural stiffness in all directions, it is preferable that α is between 45° and 90°. More preferably, a is approximately 90° and a maximum stiffness is achieved in all directions. In the case of a structural part of somewhat larger size which is assembled from a number of strip-like profiled sheets, it is preferable for the profiled sheets to be more than twice as long as they are wide. This introduces, as it were, a greater continuity into the structural part produced, which enhances its stiffness and strength. More preferably, in such a case, the longitudinal direction of the profiled sheets is perpendicular to the axis of the greatest flexural stiffness. Model strength calculations have shown that, if these conditions are met, a maximally flexurally stiff structure can be obtained.

The structural part according to the invention can be thought of as being constructed by drawing mutually joining diagonals in the four side faces of an imaginary rectangular prism, which diagonals form, as it were, an outermost delineation of the shell roof and, according to the invention, then fitting, for example, somewhat twisted strips profiled in corrugated-sheet fashion in a crossing manner between mutually oppositely situated diagonals.

The invention is thus also embodied in a doubly curved, shell -like structural part composed mainly of at least two twisted profiled sheets joined to one another in a crossing manner. In this connection, it is preferable for the profiled sheets to have a corrugated- sheet-like profiling having, for example, a trapezoidal corrugation.

DISCUSSION OF THE FIGURES

The invention will now be explained in greater detail by reference to the drawing, in which: Figure 1 shows a portion of a structural part according to the invention,

Figure 2 diagrammatically shows the structure of a shell roof according to the invention.

In Figure 1, 1 is a first profiled sheet having a trapezoidal corrugated-sheet-like profiling and 2 is a similar second profiled sheet which is joined with the aid of joining components, which are not shown, to the first profiled section 1 in a perpendicular orientation, that is to say with a = 90°. Figure 2 shows a rectangular prism. If mutually joining diagonals are now provided in the side faces of the prism and profiled sheets are laid over one another in a crossing manner and joined to one another according to the invention between mutually oppositely situated diagonals, an extremely stiff roof or roof part is obtained. It will be clear that it is possible to vary the basic shape, for example the heights, or the lengths of the sides of the base plane of the prism. Such walls, roofs and parts thereof can readily be constructed in steel or aluminium, the profiled sheets being joined to one another, for example, by a blind joining technique.

Claims

1. Method for producing a doubly curved shell -like structural part, for example a so-called hyparshell roof, by joining at least two profiled sheets each having an imaginary axis of greatest flexural stiffness in the neutral plane of the profiled sheet to one another with their axes of greatest flexural stiffness essentially in one plane at an angle or differing from 0° after they have been twisted around an axis of lower flexural stiffness.

2. Method according to Claim 1, wherein 45° ≤ a ≤ 90° .

3. Method according to Claim 1 or 2 , wherein a is approximately 90°.

4. Method according to one of the preceding claims, wherein elongated profiled sheets which are more than twice as long as wide are chosen for the profiled sheets.

5. Method according to Claim 4, wherein profiled sheets are chosen which have a longitudinal direction which is perpendicular to the axis of greatest flexural stiffness.

6. Doubly curved shell-like structural part, essentially composed of at least two twisted profiled sheets joined to one another in a crossing manner.

7. Structural part according to Claim 6, wherein the profiled sheets have an undulating profiling.

8. Structural part according to Claim 7, wherein the profiling is trapezoidal.