Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

An investigation of crack propagation with a wedge indenter to improve rock fragmentation efficiency

Filetype[PDF-12.53 MB]


Select the Download button to view the document
This document is over 5mb in size and cannot be previewed
  • English
    • Details You May Also Like

    Details:

    • Personal Author:
    • Corporate Authors:
      United States. Bureau of Mines.
    • Description:
      "The Bureau of Mines conducted basic experiments to study the process of crack propagation with a wedge indenter. The work was conducted under plane stress conditions in a hard, brittle limestone. The purpose of these experiments was to first gain an understanding of the basic crack propagation process under a sharp indenter, and second, to determine how the crack propagation process could be used to improve mechanical fragmentation systems. Three methods of rock fracture with the wedge indenter were investigated in this program. These were the confined indentation tests, the unconfined splitting tests, and the edge chipping tests. The confined indention tests represent worse case conditions for crack growth, and formed the lower bound on fracture efficiency. The unconfined splitting tests represented best case conditions and fixed the upper bound of fracture efficiency. The edge chipping tests represented an idealized fragmentation process based exclusively upon the highly efficient fracture propagation process. Edge chipping achieved a specific energy of 25 in.Lbf/in3 compared with conventional drag cutters, which required a specific energy of at least 2,385 in.Lbf/in3. Thus edge chipping is up to 100 times more efficient than conventional drag cutting. Because of these promising results, more work is planned with the fracture propagation process in three dimensions." - NIOSHTIC-2

      NIOSH no. 10005778

    • Subjects:
    • Series:
      Report of investigations (United States. Bureau of Mines) ; 9106
    • Document Type:
      Report
    • Collection(s):
    • Main Document Checksum:
    • Download URL:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at stacks.cdc.gov