In this paper, influence of riveting process parameters, namely, riveting force, sheet thickness, friction coefficient and clearance fit are investigated on residual stress field and fatigue life of single riveted lap joint of AA2024 type. According to the effect of riveting induced residual stresses on fatigue life of riveted lap joint, these parameters are optimized to maximize the residual s...

To obtain the characteristic life of a chain tool magazine and automatic tool changer under normal working condition, a small-sample accelerated life test method was developed. The inverse power law model and small-sample virtual augmented theory was applied while taking vibration as the accelerated stress. The accelerated life test of the automatic tool changer was carried out under different ...

BACKGROUND This study examined the relation between stress and change in emotional and behavioural problems in children and adolescents referred for mental health services. METHOD At three waves across four years, children and their parents (N = 310, mean age at the first wave = 11.26 years, SD = 3.18) reported emotional and behavioural problems, as well as stressful life events (parent repor...

absract  background: stress urinary incontinence is a common problem in the middleaged  women and can affect their quality of life. this study evaluated the effects of  pelvic floor muscle exercise on quality of life outcomes in women with stress urinary  incontinence .  methods: after baseline evaluation, 50 women were assigned for this clinical trial .  participants were instructed to do pelv...

BACKGROUND Hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, associated with increased pituitary volume, may mediate observed alterations in stress reactivity in patients with psychotic disorder. We examined the association between pituitary volume, real-life stress reactivity and genetic liability for psychotic disorder. METHOD Pituitary volumes were derived from magnetic resonance im...

Vibration fatigue test and analysis methodology for flip chip solder joint fatigue life assessment have been developed by performing vibration tests with constant G-level and varying G-level input excitation. The linear cumulative damage analysis method (Miner’s rule) predicts non-conservative result for vibration fatigue life of flip chip solder joint. Finite element analysis (FEA) using a glo...

This study presents a design criterion developed for fatigue strengthening of a 120-year-old metallic railway bridge in Switzerland and presents a pre-stressed un-bonded reinforcement (PUR) system developed to apply the strengthening. The PUR system uses carbon fiber reinforced polymer (CFRP) plates; however, unlike conventional pre-stressed CFRP reinforcement methods, preparation of the existi...

Fretting fatigue process have many features such as early stage crack initiation at contact edge, very slow crack propagation and fatigue failure after very long life operation. In this paper at first we present fretting fatigue model in high cycle region, which is considering the wear process near contact edge. And then we present fretting fatigue life estimation method in low cycle fatigue re...

objective : the findings demonstrated that parents of children with cerebral palsy experience elevated levels of distress, depression, anxiety, posttraumatic stress symptom and subjective symptom of stress and low quality of life. effective interventions targeting relapse have the potential to dramatically reduce the point prevalence of this condition. many studies have shown that mindfulness b...