Fracture Control Methods for Space Vehicles VolumeⅠ, Fracture Control Design Methods

摘要

This report is concerned with a systematic approach for applying methods for fracture control in the structural components of space vehicles. Four major steps are required to complete the fracture control sequence. The first step is to define the primary load-carrying structural elements and the type of load, environment, and design stress levels acting upon them. The second step is to identify the potential fracture-critical parts by means of a selection logic flow diagram. The third step is to evaluate the safe-life and fail-safe capabilities of the specified part. The last step in the sequence is to apply the control procedures that will prevent damage to the fracture-critical parts.nThe fracture control methods discussed herein include fatigue design and analysis methods, methods for preventing crack-like defects, fracture mechanics analysis methods, and nondestructive evaluation methods;however, emphasis is placed on the fracture mechanics analysis methods. To illustrate the use of fracture mechanics methodology, an example problem is presented for evaluation of the safe-crack-growth capability of the Space Shuttle crew compartment skin structure.