## Abatraet-Design requirements have been developed to insure structural safety for current and future USAF aircraft. New structure is assumed to be flawed. Materials, stress levels and structural arrangements are chosen so as to prevent damage from growing to catastrophic size prior to detection.
The application of fracture mechanics to the testing of wood
โ Scribed by G. Prokopski
- Publisher
- Springer
- Year
- 1993
- Tongue
- English
- Weight
- 393 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0022-2461
No coin nor oath required. For personal study only.
โฆ Synopsis
The problem of a mode I fracture toughness of wood is considered. After a short discussion of relevant literature the test results concerning mode I fracture on three types of wood and the obtained values of stress intensity factor, K~c, are discussed. The compressive and tensile strength of the wood fibres and flexural strength are also presented. A considerable variation of the stress intensity factor, K~c, has been found to depend on the wood species and the direction of taking specimens for tests. The character of a failure process and the obtained values of the stress intensity factor, K~o, were determined by interrelations of cohesion forces existing between particular components of the wood structure, and by anisotropy of the wood. Both the compressive and tensile strength tests performed along the fibres and the bending strength tests,crosswise to the fibres have not confirmed the tendencies observed in the fracture toughness tests. The investigations performed show the usefulness of fracture mechanics for evaluation of the strength properties of wood. It is concluded that materials science must consider wood as a valuable and rewarding material upon which to focus research efforts.
๐ SIMILAR VOLUMES
A theoretical method was developed for calculating the stress intensity factor (K) for semielliptical surface cracks in shafts subjected to a constant moment load. A number of tests using 2and 3-dimensional photoelasticity showed good agreement with the theoretical model. The calculated K was then u