1.1 Scope of EN 1999-1-5 (1) EN 1999-1-5 applies to the structural design of aluminium structures, stiffened and unstiffened, that have the form of a shell of revolution or of a round panel in monocoque structures. (2) EN 1999-1-5 covers additional provisions to those given in the relevant parts of EN 1999 for design of aluminium structures. NOTE Supplementary information for certain types of shells is given in EN 1993-1-6 and the relevant application parts of EN 1993 which include: - Part 3-1 for towers and masts; - Part 3-2 for chimneys; - Part 4-1 for silos; - Part 4-2 for tanks; - Part 4-3 for pipelines. (4) The provisions in EN 1999-1-5 apply to axisymmetric shells (cylinders, cones, spheres) and associated circular or annular plates, beam section rings and stringer stiffeners, where they form part of the complete structure. (5) Single shell panels (cylindrical, conical or spherical) are not explicitly covered by EN 1999-1-5. However, the provisions can be applicable if the appropriate boundary conditions are duly taken into account. (6) Types of shell walls covered in EN 1999-1-5 can be (see Figure 1.1): - shell wall constructed from flat rolled sheet with adjacent plates connected with butt welds, termed “isotropic”; - shell wall with lap joints formed by connecting adjacent plates with overlapping sections, termed “lap-jointed”; - shell wall with stiffeners attached to the outside, termed “externally stiffened” irrespective of the spacing of stiffeners; - shell wall with the corrugations running up the meridian, termed “axially corrugated”; - shell wall constructed from corrugated sheets with the corrugations running around the shell circumference, termed “circumferentially corrugated”. [Figure 1.1 - Illustration of cylindrical shell form] (7) The provisions of EN 1999-1-5 are intended to be applied within the temperature range defined in EN 1999-1-1. The maximum temperature is restricted so that the influence of creep can be neglected. For structures subject to elevated temperatures associated with fire, see EN 1999-1-2. (8) EN 1999-1-5 does not cover the aspect of leakage. 1.2 Assumptions (1) The general assumptions of EN 1990 apply. (2) The provisions of EN 1999-1-1 apply. (3) The design procedures are valid only when the requirements for execution in EN 1090-3 or other equivalent requirements are complied with. (4) For the design of new structures, EN 1999 is intended to be used, for direct application, together with EN 1990, EN 1991, EN 1992, EN 1993, EN 1994, EN 1995, EN 1997 and EN 1998. (5) EN 1999 is intended to be used in conjunction with: - European Standards for construction products relevant for aluminium structures; - EN 1090-1, Execution of steel structures and aluminium structures - Part 1: Requirements for conformity assessment of structural components; - EN 1090-3, Execution of steel structures and aluminium structures - Part 3: Technical requirements for aluminium structures.