Visar resultat 1 - 5 av 8 avhandlingar innehållade ordet squats.
1. Squat defects and rolling contact fatigue clusters - Numerical investigations of rail and wheel deterioration mechanisms
Sammanfattning : Squat defects, a type of localised rolling contact fatigue damage appearing on rail surfaces with rail break as an ultimate consequence, have concerned infrastructure managers for the last couple of decades. In recent years similar types of defects—so-called studs—that are visually resembling squats, have started to appear. LÄS MER
Sammanfattning : Despite signiﬁcant eﬀorts throughout the last decades, the mechanisms behind the formation of squats — a form of rolling contact fatigue (RCF) damage in rails — are not fully understood. Proposed causes of initiation involve, but are not limited to, small initial rail surface irregularities which yield high contact stresses, rail corrugation and varying friction conditions. LÄS MER
Sammanfattning : A major concern for the railway industry today is the problem of rolling contact fatigue (RCF) damage in wheels and rails as a result of increased traffic, accelerations, and loading conditions. The wheel/rail contact condition that occurs in railway applications is complex, and it is essential to understand the associated damage from combined mechanical and thermal loadings in order to predict component life and develop appropriate maintenance systems. LÄS MER
4. Altered movement patterns and deviating muscular activity in individuals with anterior cruciate ligament injury
Sammanfattning : The purpose of this thesis was to increase the understanding of altered movement patterns in individuals with anterior cruciate ligament (ACL) injury in order to improve ACL rehabilitation, and to develop an observational instrument termed Test for Substitution Patterns (TSP) for standardized, quantifiable scoring of altered movement patterns in legs and trunk. In all, 142 participants, 93 with ACL-rupture (37 women) and 49 uninjured participants were investigated. LÄS MER
Sammanfattning : This thesis concerns issues regarding the modeling and numerical simulation of singularcracks and their propagation in the context of Rolling Contact Fatigue (RCF) in rails.Typically, such cracks are associated with squats and head-checks in the rail head. LÄS MER