Fundamentals in the Development of Reliable Structural Components?

by Prof. Dr. Ralf Cuntze

Modernlight-weight structures are the result of an optimisation compromise between allt he product’s functional requirements (e.g. stiffness, strength) and all the operational requirements (e.g. lifetime). Very often the strength requirement determines the mass. Design driving hereby are the material properties and the failure conditions for fracture and yielding (functional design verification). Responsible for the quality of a structural component achieved under the minimum mass requirement area qualified analysis procedure, a reliable data input including the dimensioning load cases, and the safety concept. Special task of the designer is the development of a so-called robust structure which does not essentially change its behaviour under the usual scatter of the stochastic parameters with short comings for the fulfilment of its functions. Due to above aspects the following elements will be dealt with

1. Problem Description

2. Introduction to Design Dimensioning and Design Verification (Nachweis)

3. Safety Concept Applied

4. Input of Appropriate Properties for Linearand Non-linear Analysis

5. Design Limit Loads, Dimensioning Load Cases, Load Interaction Failure

6. Link Deterministic to Probabilistic Design.

Also, the definitions of somenotions such as Design Limit Load (Sichere Last) and Dimensioning Load Case are presented. Finally, an application of the reliability analysis to the ARIANE 5 Boosters shall demonstrate the use fulness.