Repository logo

Browsing by Subject "cracks"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • thumbnail.journal.alt
    Item type:Article, Access status: Open Access ,
    Criterion for angle prediction for the crack in materials with random structure
    (2011) Podgórski, Jerzy
    Presented paper contains results of fracture analysis of brittle composite materials with a random distribution of grains. The composite structure has been modelled as an isotropic matrix that surrounds circular grains with random diameters and space position. Analyses were preformed for the rectangular 'numerical sample' by finite element method. FE mesh for the examples were generated using the authors' computer program RandomGrain. Fracture analyses were accomplished with the authors' computer program CrackPath3 executing the 'fine mesh window' technique. Calculations were preformed in 2D space assuming the plane stress state. Current efforts focus on brittle materials such as rocks or concrete.
  • thumbnail.journal.alt
    Item type:Article, Access status: Open Access ,
    Sheave axles of mine shaft hoists - difficulties and limitations in assessing their technical condition during in-service tests
    (Wydawnictwa AGH, 2021) Straszak, Sławomir; Wiktor, Artur
    The paper discusses the difficulties and limitations in the possibility of assessing the technical condition of sheave axles during in-service tests resulting from the lack of access to many areas of the outer surface of the axle due to built-in bearings and mounted sheaves, as well as from the complex shape of some types of axles. Examples of inservice axle failures are given and the causes are discussed. In addition, information on the legal basis for performing non-destructive testing of sheave axles in service, technical requirements for sheave axles, critical areas found in axles, theoretical basis for ultrasonic testing, and testing techniques including the latest phased array method is presented.