Efficient implicit simulation for incremental forming

Single Point Incremental Forming (SPIF) is a displacement controlled process performed on a CNC machine. A clamped blank is deformed by the movement of a small sized tool that follows a prescribed tool path. An extensive overview of the process has been given in [1]. The tool size plays a crucial role in the SPIF process. The small radius of the forming tool concentrates the strain at the zone of deformation in the sheet under the forming tool. The tool has to travel a lengthy forming path all over the blank to introduce the deformation. Numerically, this requires performing thousands of load increments on a relatively fine FE model resulting in enormous computing time. A typical computing time for implicit simulation of a small academic test is measured in by days. The focus of this paper is to efficiently use the implicit time integration method in order to reduce the required computing time for incremental forming implicit simulation drastically

Stable incremental deformation of a strip to high strain

This paper presents the effect of combined stretching and bending on the achieved strain in\ud incremental sheet forming ISF. A simple two dimensional model of strip undergoing stretching and\ud travelling three point bending in cyclic form is used. The numerical model presents the effect of the\ud ratio of stretching velocity to roll-set speed on the achieved strain and its distributio

A Meta-analysis to Assess the Effectiveness of a Procedural Scale to Measure Pain in a Child Aged 0-1 Year

Background: The burden of pain in newborns has been investigated in several studies, but little is known about the appropriateness and effectiveness of using pain scales according to the specific type of pain or the condition of the infant. Our purpose was to conduct a meta-analysis to assess and report on the effectiveness of the used procedural pain scale to measure pain in a child over 0-1years reflecting that by using the non-pharmacological interventions in pain reduction in randomized trials. Methods: A systematic search was performed up to October 2021 in PubMed and Cochrane Library The current review enrolled randomized clinical trials (RCTs). It was also conducted according to PRISMA guidelines. Cochrane's risk of bias assessment was used to assess the studies' quality and risk of bias. Meta-analyses were performed by calculating the standardized mean difference (SMD) at a 95% confidence interval (CI) using Review Manager Software Results: 50 trials were found 8 trials were included in this meta-analysis. Most of the studies related to procedural pain (heel lance and vaccination), Three validated pain scales were used in all trials (neonatal infant pain scale NIPS, premature infant pain profile PIPP, AND neonatal pain, agitation, and sedation scale NPASS. The Meta-analysis showed significant effect of non- pharmacological interventions (swaddling, mother holding, sucrose) in pain reduction compared with control group (SMD 1.2, 95% CI -1.88 to -.52, P =0.0005), I` = 95%, P> 0.00001. The 8 studies with 918 infant’s participants entered into analysis used effective pain scales (NIPS, PIPP, and NPASS) to measure procedural pain effectively Conclusions: overall the non-pharmacological interventions show positively effect in pain reduction, these mean the pain scales that are used in studies appropriate to assess pain when measure procedural pain (heel lice, vaccination), however, there is no consistency about the best tool to use in children related to several factors

Melatonin serum level, sleep functions, and depression level after bilateral anodal transcranial direct current stimulation in patients with Parkinson’s disease: a feasibility study

Objective: Parkinson’s disease (PD) is associated with non-motor complications such as sleep disturbance and depression. Transcranial direct current stimulation (tDCS) showed therapeutic effects on the motor dysfunctions. However, the potential effects of tDCS therapy on melatonin hormone, sleep dysfunctions, and depression in patients with PD still unclear. This feasibility study aimed to identify any potential changes in melatonin serum level, sleep functions and depression after the bilateral anodal tDCS in patients with PD. Material and Methods: Tensessions of bilateral anodal tDCS stimulation applied over left and right prefrontal and motor areas were given to twenty-five patients with PD. Melatonin serum level, Pittsburgh sleep quality index, and geriatric depression scale examined before and after tDCS stimulation. Results: After bilateral anodal tDCS, there was a significant reduction in melatonin serum level, improvement in depression, improvements in overall sleep quality, and sleep latency. Correlations test showed significant associations between melatonin serum level reduction and changes in subjective sleep quality, and sleep duration, as well as between improvements in depression and overall sleep quality, sleep latency, and sleep disturbance.Conclusion: Bilateral anodal tDCS therapy was a feasible and safe tool that showed potential therapeutic effects on melatonin serum level, sleep quality, and depression level in patients with PD. Although the further large scale and randomized-control trial studies are crucially needed, there is still a need for such a feasibility study to be established before such trials can be implemented as is recommended in the new medical research council guidelines

Investigation of material deformation mechanism in double side incremental sheet forming

Double side incremental forming (DSIF) is an emerging technology in incremental sheet forming (ISF) in recent years. By employing two forming tools at each side of the sheet, the DSIF process can provide additional process flexibility, comparing to the conventional single point incremental forming (SPIF) process, therefore to produce complex geometries without the need of using a backing plate or supporting die. Although this process has been proposed for years, there is only limited research on this process and there are still many unanswered open questions about this process. Using a newly developed ISF machine, the DSIF process is investigated in this work. Focusing on the fundamental aspects of material deformation and fracture mechanism, this paper aims to improve the understanding of the DSIF process. Two key process parameters considered in this study include the supporting force and relative position between master and slave tools. The material deformation, the final thickness distribution as well as the formability under varying conditions of these two process variables are investigated. An analytical model was developed to evaluate the stress state in the deformation zone. Using the developed model, an explicit relationship between the stress state and key process parameters was established and a drop of stress triaxiality was observed in the double contact zone, which explains the enhanced formability in the DSIF process. Based on the analytical and experimental investigation, the advancements and challenges of the DSIF process are discussed with a few conclusions drawn for future research