1.1 Scope of prEN 1993-1-7
(1) prEN 1993-1-7 provides rules for the structural design of assemblies of unstiffened and stiffened steel plates whose elements are under predominantly distributed transverse loads.
(2) prEN 1993-1-7 is applicable to containment structures such as silos, tanks, digesters and lock gates, where the external actions chiefly act transversely on their individual plates or panels. Where a plate or panel under bending is additionally subject to membrane forces that have a significant effect on the resistance, this document covers assessment of the resistance through its computational analysis procedures.
(3) prEN 1993-1-7 is applicable to structures with rectangular, trapezoidal or triangular component plate segments, each with one axis of symmetry.
(4) prEN 1993-1-7 does not apply to plates or panels where the dominant structural resistance requirement relates to membrane forces in the plates (for these, see EN 1993-1-5).
(5) prEN 1993-1-7 does not apply to plates or panels whose curvature (out of flatness) exceeds that defined in 1.1 (14). For such curved plates, see EN 1993-1-6.
(6) prEN 1993-1-7 does not apply to circular or annular plates. For such plates, see EN 1993 1-6.
(7) prEN 1993-1-7 does not apply to cold-formed sheeting. For such plates, see EN 1993-1-3.
(8) This document is only concerned with the requirements for design of plates and plate assemblies against the ultimate limit states of:
- plastic failure;
- cyclic plasticity;
- buckling;
- fatigue.
(9) Overall equilibrium of the structure (sliding, uplifting, or overturning) is not included in this document. Special considerations for specific applications are available in the relevant applications parts of EN 1993.
(10) The rules in this document refer to plate assemblies that are fabricated using unstiffened or stiffened plates or panels. The document is also applicable to the design of individual plates or panels that are predominantly subject to actions transverse to the plane of each plate. Both frictional actions on the plate surface and forces imposed by adjacent components of the plate assembly also induce in-plane actions in each plate.
(11) This document gives algebraic rules and guidance to account for bending with small membrane forces in the individual plates or panels. Where an unstiffened or stiffened plates or panels is subject to significant magnitudes of both bending and in-plane forces, the computational analysis procedures of this document apply.
(12) Where no application part defines a different range, this document applies to structures within the following limits:
- design metal temperatures within the range −50 °C to +100 °C;
- the geometry of individual plate segments is limited to rectangular, triangular and trapezoidal shapes with b/t greater than 20, or b1/t greater than 20, as appropriate (see Figure 3.2);
- Single plate elements are treated as flat where the deviation from flatness e0 meets the condition (see Figure 9.1). Where this criterion is not met, it is appropriate to treat the plate as a shell panel (see EN 1993-1-6).
1.2 Assumptions
(1) Unless specifically stated, the provisions of EN 1990, EN 1991 (all parts) and EN 1993 (all parts) apply.
(2) The design methods given in prEN 1993-1-7 are applicable if:
- the execution quality is as specified in EN 1090 2, and
- the construction materials and products used are as specified in the relevant parts of EN 1993 (all parts), or in the relevant material and product specifications.
(3) The provisions in this document apply to materials that satisfy the brittle fracture provisions given in EN 1993-1-4 and EN 1993-1-10.
(4) In this document, it is assumed that wind loading, seismic actions and bulk solids flow can, in general, be treated as quasi-static actions.
