Accession Number : ADA192957

Title :   Influence of Microstructure and Microdamage Processes on Fracture at High Loading Rates.

Descriptive Note : Annual rept. 1 Feb 87-31 Jan 88,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Giovanola, J H ; Shockey, D A

PDF Url : ADA192957

Report Date : 03 Mar 1988

Pagination or Media Count : 20

Abstract : The optimal use of advanced beta and near-beta titanium alloys in situations involving dynamic or shock loading requires an understanding of the influence of microstructure and loading rate on fracture behavior. To address this need, SRI is performing dynamic crack initiation and propagation experiments on Ti-1OV-2Fe-3Al in three microstructural conditions, varying the loading rate to establish the rate-dependence of the fracture toughness. A new experimental method developed in a previous Air Force Office of Scientific Research program (the one point bend impact test) and numerical simulations of the experiments are used to determine dynamic initiation and propagation toughness. Further, the fracture surface topography analysis (FRASTA) technique is applied to the fractured specimens to elucidate the microstructural failure mechanisms controlling fracture in each of the investigated microstructures. Keywords: Microstructure, Dynamic fracture, Initiation toughness, Propagation toughness, Titanium alloys, Iron alloys, Aluminum alloys.

Descriptors :   *CRACKING(FRACTURING), *MICROSTRUCTURE, *TITANIUM ALLOYS, ALUMINUM ALLOYS, DYNAMIC LOADS, DYNAMICS, FAILURE, FRACTURE(MECHANICS), IRON ALLOYS, LOADS(FORCES), NUMERICAL ANALYSIS, OPTIMIZATION, RATES, SHOCK(MECHANICS), SURFACE ANALYSIS, TOPOGRAPHY, TOUGHNESS, CRACK PROPAGATION

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE