Fully Dynamic Numerical Simulation of the Hammer Peening Fatigue Life Improvement Technique

AbstractThis paper presents the results of the development process for a Finite Element Analysis of the Hammer Peening Fatigue Life Improvement Technique. The Fatigue Life of welded structures is still in need for improvement. The sheer number of Fatigue Live Improvement Techniques parameters leads to the need of simulating and predicting their results. For this study, two different materials were used, an Austenitic Stainless Steel and a Duplex Stainless Steel. Non-load carrying cruciform weld joints were produced and fatigue tested, with and without the Hammer Peening treatment. Finally a FEA code (ABAQUS®) was used to simulate the Hammer Peening technique. A fully dynamic model was used, combined with the Chaboche Kinematic-hardening material model and different Hammering parameter experimentally determined. Alongside the residual stresses introduced by the Hammer Peening Technique, the predicted Fatigue Life using the FEA model were compared with the experimental results, showing a very good agreement between them. Also the effect of several parameters, like the hammering impact load, the hammer positioning or the number of hammering passages, were analysed as a way to validate the FEA model. The most important result was of course the Fatigue Strength Gain factor, for the Hammer Peening Technique, that in both cases was found to be superior to 1.3

Implementing mentor mothers in family practice to support abused mothers: Study protocol

Contains fulltext : 97988.pdf (postprint version ) (Open Access)ABSTRACT: BACKGROUND: Intimate partner violence is highly prevalent and mostly affects women with negative consequences for their physical and mental health. Children often witness the violence which has negative consequences for their well-being too. Care offered by family physicians is often rejected because abused women experience a too high threshold. Mentor mother support, a low threshold intervention for abused mothers in family practice, proved to be feasible and effective in Rotterdam, the Netherlands. The primary aim of this study is to investigate which factors facilitate or hinder the implementation of mentor mother support in family practice. Besides we evaluate the effect of mentor mother support in a different region. METHODS/DESIGN: An observational study with pre- and posttests will be performed. Mothers with home living children or pregnant women who are victims of intimate partner violence will be offered mentor mother support by the participating family physicians. The implementation process evaluation consists of focus groups, interviews and questionnaires. In the effect evaluation intimate partner violence, the general health of the abused mother, the mother-child relationship, social support, and acceptance of professional help will be measured twice (t = 0 and t = 6 months) by questionnaires, reporting forms, medical records and interviews with the abused mothers. Qualitative coding will be used to analyze the data from the reporting forms, medical records, focus groups, interviews, and questionnaires. Quantitative data will be analyzed with descriptive statistics, chi square test and t-test matched pairs. DISCUSSION: While other intervention studies only evaluate the feasibility and effectiveness of the intervention, our primary aim is to evaluate the implementation process and thereby investigate which factors facilitate or hinder implementation of mentor mother support in family practice.6 p

Healthcare utilization by abused women: a case control study.

Item does not contain fulltextBACKGROUND: Previous studies observed an association between intimate partner violence (IPV) and increased health problems. Early detection of IPV by general practitioners (GPs) is required to prevent further harm and provide appropriate support. In general practice, a limited number of studies are available on healthcare utilization of abused women. OBJECTIVES: The aim of the study was to investigate the healthcare utilization of abused women compared to non-abused. METHODS: The study was designed as a matched case-control study in 16 general practices in deprived areas in Rotterdam (The Netherlands). Electronic medical files of 50 victims of IPV were analysed for consultation frequency, referrals, medical prescription and reasons for encounter over a period of five years. Controls (n= 50) were non-abused women matched for general practice, age, number of children, and country of origin and education level. RESULTS: Abused women visited their GP almost twice as often than non-abused, in particular for social problems (OR= 3.5; 95%CI: 1.2-10.5; P= 0.01), substance abuse (OR= 4.6; 95%CI: 0.9-22.7; P= 0.05) and reproductive health problems (OR= 3.0; 95%CI: 1.3-6.8; P= 0.009). Victims of IPV were significantly more often referred for additional diagnostics (OR= 3.6; 95%CI: 1.1-12.2; P= 0.03), to mental healthcare (OR= 2.9; 95%CI: 1.2-7.1; P= 0.02) than non-victims. Abused women received 4.1 times more often a prescription for anti-depressants (95%CI: 1.5-11.6; P= 0.005) than non-abused women. CONCLUSION: As compared to non-abused women, female victims of IPV visited their GP more frequently and exhibited a typical pattern of healthcare utilization. This could alert GPs to inquire about partner abuse in the past.1 juni 201

"Young people, adult worries": RCT of an internet-based self-support method "Feel the ViBe" for children, adolescents and young adults exposed to family violence, a study protocol

Contains fulltext : 116440.pdf (publisher's version ) (Open Access)BACKGROUND: Violence in families affects children. Exposure to violence is seen as child abuse. Figures show that about one third of children exposed to violence become victim or perpetrator in their adult life: known as intergenerational transmission. Violence also affects sexual and reproductive health. To prevent problems in adult life, children need help and support. However, while trying to protect their parents, children often do not seek help, or perceive the threshold as too high. Since almost all children of the current generation have access to the internet, an online intervention will make help better available for this target group. In 2011, an internet-based self-support method for children, adolescents and young adults exposed to family violence was developed in the Netherlands: "Feel the ViBe". The intervention was developed in close collaboration with the target group. This article describes the protocol of the RCT to study the effectiveness of this intervention. METHODS/DESIGN: This study is a randomized controlled trial using the method of minimization to randomize the participants in two parallel groups with a 1:1 allocation ratio, being an intervention group, having access to "Feel the ViBe" and usual care (UC), and a control group, having access to minimally enhanced usual care (mEUC) followed by access to the intervention after twelve weeks. Outcomes are measured with questionnaires on PTSD symptoms, mental health and sexual and reproductive health. Routine Outcome Measurement (ROM) will be used to measure a direct effect of participating in the intervention. Data from a web evaluation questionnaire (WEQ), user statistics and qualitative analysis of online data will be used to support the findings. To compare results Cohen's d effect sizes will be used. DISCUSSION: A RCT and process evaluation will test effectiveness and provide information of how the effects can be explained, how the intervention meets the expectation of participants and which possible barriers and facilitators for implementation exist. A qualitative analysis of the data will add information to interpret the quantitative data. This makes "Feel the ViBe" unique in its field. TRIAL REGISTRATION: The Netherlands National Trial Register (NTR), trial ID NTR3692.11 p