The Mechanics of Failure at Connections: Size Effects and Scaling

Abstract

The integrity of engineering structures is often limited by the fracture resistance at connections. This is particularly the case when materials having large differences in mechanical properties are joined. Research directed at the direct calculation of fracture at interfaces and connections under dynamic loading conditions was carried out. The accomplishments under this grant include: 1. showing that the ductile-brittle transition temperature for welds as measured in the Charpy impact test is a structural not a material property; 2. predicting intersonic crack growth along an interface in excellent agreement with experiment; 3. developing a partition of unity based methodology applicable when crack growth is discontinuous; 4. finding a 3-dimensional effect that leads to brittle cleavage failure under impact loading earlier than predicted by a two dimensional plane strain analysis; and 5. analyses and experiments that reveal the rich phenomenology that occurs under dynamic frictional sliding including a variety of pulse-like modes and the supersonic propagation of trailing pulses with much of the predicted phenomenology also seen in experiments.

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Document Details

Document Type
Technical Report
Publication Date
Mar 16, 2005
Accession Number
ADA430838

Entities

People

  • Alan Needleman

Organizations

  • Brown University

Tags

DTIC Thesaurus Topics

  • Charpy Impact Tests
  • Ductile Brittle Transition
  • Elastic Properties
  • Engineering
  • Fracture (Mechanics)
  • Impact Tests
  • Low Temperature
  • Materials
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Physics
  • Resistance
  • Three Dimensional
  • Transition Temperature
  • Transitions
  • Two Dimensional

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Materials Science (Mechanical Engineering).
  • Systems Analysis and Design

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Flow