bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure Prediction of Bonded Joints of Composite Engineering Structures
Authors: Bogdanovich Alexander E. , Yushanov Sergei P. 
Published: January 2022

Abstract
First part of the paper presents brief review of fracture mechanics applications to progressive failure prediction in adhesive bonded joints under mechanical loading end environmental effects (temperature and moisture) typical for the aircraft and civil engineering structures. Existing concepts of critical energy release rates and critical stress intensity factors for fracture modes I and II are evaluated in the context of failure and durability of adhesive bonded joints. The challenging problem of reliable experimental fracture toughness characterization of bonded laminated composites is emphasized.
Second part of the paper presents novel development of 3-D variational analysis aimed at predicting crack propagation in adhesive composite bonded joints exposed to mechanical loading combined with variable temperature and moisture. A general 3-D variational thermo-hygro-mechanical approach is developed, based on the principle of minimum total potential energy. A brick-type composite mosaic model is allowing to incorporate the material property variation in all three coordinate directions. The displacement field in each of the bricks is approximated in terms of triple series with Bernstein basis functions of an arbitrary degree used in all the coordinate directions. In the case of no pre-existing cracks, all of the bricks are perfectly bonded through the displacement continuity conditions. If there is a 2-D surface crack perpendicular to one of the coordinate axes (the crack can be arbitrarily located inside the structure, including any part of the interfaces or bondlines), then the respective displacement continuity conditions are released along the corresponding surface area. A progressive failure analysis approach is then developed using the energy release rates evaluated for various possible scenarios of a cohesive, adhesive or interlaminar crack propagation. Several cracks of the same type or different types can be analyzed simultaneously.
Numerical examples illustrate application of the developed analysis approach to double-lap adhesive bonded joints with cross-ply laminated composite adherends under some typical thermomechanical loading cases. The moisture effect is incorporated through the time-dependent critical energy release rates for Modes I and II. Several pre-existing cracks are introduced (separately or conjointly), and their propagation is followed using the computed strain energy release rates around the crack tip. Importantly, each of the distinct failure modes (adhesive, cohesive or interlaminar) is characterized by its specific critical strain energy release rate sensitive to the penetrating moisture. Numerical results and their comparison with available experimental data show that the developed analysis approach is capable of predicting the paths of dominating failure modes in adhesively bonded laminated composite joints.
Applications of Composite Grid Structures
Authors: Tsai Stephen W. 
Published: January 2022

Abstract
Composite grids have been exploited by users in the US, USSR, Japan, Germany, South Africa and no doubt others over the last twenty years. Most efforts suffered lack of manufacturing processes suitable for mass production. Our attempts during the last few years have produced several grid forms that show promise for commercialization. These processes are fundamentally different from the conventional laminated or woven structures currently in use.
Fabrication, Testing and Analysis of Composite Sandwich Structures
Authors: Daniel Isaac M. , Abot R. A. Jandro 
Published: January 2022

Abstract
The objective of this work was to study the behavior of composite sandwich structures and develop simple models to explain this behavior as a function of material, geometric and loading parameters. The scope of the study consists of mechanical characterization of the sandwich constituent materials, i. e., composite facings, honeycomb or foam cores, and adhesive layers; fabrication and testing of sandwich beams in pure bending; identification and recording of failure mechanisms by direct observation and nondestructive evaluation; and comparison of observed deformation and failure behavior with analytical predictions. Sandwich beams were fabricated by bonding carbon/epoxy (AS4/3501-6) facings to an aluminum honeycomb core with FM 73 film adhesive. Special techniques were developed to prevent premature failures under the loads and in the core and to insure failure in the test section under pure bending. Strains to failure in the facings were recorded with strain gages, and beam deflections and core strains were recorded with Moire techniques. The beam facings displayed characteristic nonlinearities for the composite material used, a softening nonlinearity on the compression side and a stiffening one on the tension side. These nonlinearities appear more pronounced than in the case of monotonic axial loadings of the composite material alone. The linear response of the beam is perfectly described by a simple bending model neglecting the contribution of the core, however, the more pronounced nonlinear behavior requires more accurate characterization of the core and adhesive materials separately, and more refined modeling.
Cracking of Plates With Randomly Distributed Holes by a Maximum Entropy Method
Authors: Ostoja-Starzewski M. , Al-Ostaz Ahmed , Jasiuk I. 
Published: January 2022

Abstract
It has recently been shown [1] that fracture response of nominally identical elastic-brittle (epoxy) as well as ductile (aluminum) sheets, each containing randomly distributed circular holes, is non-unique. This non-uniqueness pertains, in particular, to the resulting fracture patterns and effective stress-strain curves, whereby both of these characteristics display considerable scatter. This result points to the significant influence which microscale random noise in material parameters may have on the global, macroscopic behavior. In this paper we formulate, on the basis of a maximum entropy method [2], a stochastic fracture mechanics model for this class of problems. The method is based on the statistics of experimental data, obtained for a number of specimens, involving the inter-hole crack lengths and their angles. It allows prediction of probability distributions of damage responses and patterns of Gibbs ensembles of random hole systems such as, for example, porous materials with millions of voids.
Numerical Study of Damage Growth in Particulate Composites
Authors: Kwon Y. W. , Liu C. T. 
Published: January 2022

Abstract
A numerical study was conducted to simulate and predict damage initiation and growth around the crack tip in particulate composite specimens made of hard particles embedded in a soft rubber-like matrix material. Therefore, damage evolution in the matrix material around crack tips was investigated. The progressive damage was modelded using a micro/macro-approach which combined two levels of analyses like the micro-level and the macro-level analyses. Damage description was undertaken at the microlevel using a simplified three-dimensional unit-cell model and an isotropic continuum damage theory. The numerical study examined both thin and thick specimens with a short or long edge crack to understand the effects of specimen thickness and crack size on the damage initiation, growth, and saturation. Some numerical results were validated by experimental data.
An Information System for Damage Tolerance of Polymer Matrix Composites
Authors: Turkgenc Ozgur , Dianati Reza , Mitrovic Milan , Hahn H. Thomas , Shypyrkevich Peter 
Published: January 2022

Abstract
Much research has been conducted to understand the damage tolerance behavior of polymer matrix composites. As a result, a fair amount of data is available together with a number of analytical models. However, there are so many parameters involved that the development of a generic model is rather difficult. The present paper proposes a decision support system, which can overcome such difficulty. In the information system, a list of possible parameters is generated and used as input. The output contains compression strength after impact, dent depth and damage area as well as literature references, raw data, tables, and plots. The information system is constituted in a relational database environment and expert system technology is incorporated so that low confidence input can be captured in order to report best matching cases. Parametric studies are also made available to determine the effect of each design parameter on the damage tolerance behavior. Case examples are included to demonstrate the practical use of the software for both data retrieval and similarity studies.
A Physics Story: Literacy technique for learning the language of physics
Authors: Lincoln James 
Published: January 2022

Illustrations provided by Daniel Murrell , dansmurrell@gmail.com
When I began teaching high school physics, I found that many of my students were not just struggling with the mathematics of physics but the way the language was used. Physics is sometimes discussed as being a second language where common words are coded with specific alternate definitions (consider how you use the word “delta”). Furthermore, many of our students are English Language Learners. Thus, providing developmentally appropriate assistance to building scientific vocabulary not only addresses equity issues but can be a highly effective teaching strategy. In this article, I provide an example of one such approach to addressing literacy issues: a vocabulary building story on Convection, Conduction, and Radiation.
Generalization of Participation in Fitness Activities From Physical Education to Lunch Recess by Gender and Skill Level
Authors: Iserbyt Peter , van der Mars Hans , Drijvers Hannelore , Seghers Jan 
Published: January 2022

Purpose: Comprehensive School Physical Activity Programs aim to maximize the application of skills learned in physical education (PE) in other settings. We investigated students’ generalization of participation in fitness activities from PE to organized fitness programs during lunch recess. Method: Voluntary participation of 153 (74 girls, age 12.4 years) students from five schools in a fitness recess program before, during, and after a 12-lesson sport education fitness season in PE was assessed by gender and skill level. Moderate to vigorous physical activity was assessed through systematic observation. Results: After the sport education season, participation in fitness recess dropped from 41% to 9%, p < .001, effect size = 0.34. Average moderate to vigorous physical activity was higher in fitness (45%) compared with traditional recess (11%), p < .001, effect size = 0.50, irrespective of gender and skill level. Discussion/Conclusion: Generalization of participation in fitness activities from PE to lunch recess is a promising strategy to increase students’ moderate to vigorous physical activity.
Correlation of ganglion cell complex thinning with baseline deep and superficial macular vessel density in glaucoma
Authors: Wu Jo-Hsuan , Moghimi Sasan , Nishida Takashi , Proudfoot James A , Kamalipour Alireza , Zangwill Linda M , Weinreb Robert N 
Published: January 2022

Background/aimsTo investigate the relationship between ganglion cell complex (GCC) thinning and baseline deep and superficial macular vessel density (VD) in glaucoma.Methods97 eyes of 69 primary open-angle glaucoma (POAG) and glaucoma suspect patients from the Diagnostics Innovations in Glaucoma Study with a minimum of 4 visits and 2 years of follow-up after baseline optical coherence tomography angiography (OCTA) examination were included. OCTA 3×3 mm2macular scans were acquired at each visit and used to calculate superficial and deep parafoveal VD (pfVD) and OCT-based parafoveal GCC (pfGCC) thickness. Association of baseline superficial and deep pfVD with pfGCC thinning rate was evaluated using linear mixed model.ResultsThe included subjects had a baseline mean visual field mean deviation (95% CI) of −2.9 (–3.7 to –2.1) dB and a mean follow-up period of 3.6 years. In the univariable model, lower baseline superficial pfVD and higher mean intraocular pressure (IOP) during follow-up were significantly associated with a faster pfGCC thinning rate (p<0.05 for all), while deep pfVD was not (p=0.177). In the multivariable model, faster pfGCC thinning was correlated with higher mean IOP during follow-up (β=−0.05, p=0.002) and lower baseline superficial pfVD (β=−0.04, p=0.011). Eyes with a baseline superficial pfVD in the lowest tertile (≤46%) had significantly faster pfGCC loss compared with eyes with baseline superficial pfVD greater than 46% (p=0.015).ConclusionLower baseline superficial pfVD, but not deep pfVD, was associated with faster pfGCC thinning in glaucoma. Moreover, superficial macular VD may help predict central macula thinning in patients with glaucoma.
Ambulatory care management of 69 patients with acute severe ulcerative colitis in comparison to 695 inpatients: insights from a multicentre UK cohort study
Authors: Sebastian Shaji , Patel Kamal V , Segal Jonathan P , Subramanian Sreedhar , Conley Thomas Edward , Gonzalez Haidee Aleman , Kent Alexandra J , Saifuddin Aamir , Hicks Lucy , Mehta Shameer , Bhala Neeraj , Brookes Matthew J , Lamb Christopher A , Kennedy Nicholas A ,   PROTECT ASUC collaborators, Walker Gareth J 
Published: January 2022

IntroductionAcute severe ulcerative colitis (ASUC) traditionally requires inpatient hospital management for intravenous therapies and/or colectomy. Ambulatory ASUC care has not yet been evaluated in large cohorts.AimsWe used data from PROTECT, a UK multicentre observational COVID-19 inflammatory bowel disease study, to report the extent, safety and effectiveness of ASUC ambulatory pathways.MethodsAdults (≥18 years old) meeting Truelove and Witts criteria between 1 January 2019–1 June 2019 and 1 March 2020–30 June 2020 were recruited to PROTECT. We used demographic, disease phenotype, treatment outcomes and 3-month follow-up data. Primary outcome was rate of colectomy during the index ASUC episode. Secondary outcomes included corticosteroid response, time to and rate of rescue or primary induction therapy, response to rescue or primary induction therapy, time to colectomy, mortality, duration of inpatient treatment and hospital readmission and colectomy within 3 months of index flare. We compared outcomes in three cohorts: (1) patients treated entirely in inpatient setting; ambulatory patients subdivided into; (2) patients managed as ambulatory from diagnosis and (3) patients hospitalised and subsequently discharged to ambulatory care for continued intravenous steroids.Results37% (22/60) participating hospitals used ambulatory pathways. Of 764 eligible patients, 695 (91%) patients received entirely inpatient care, 15 (2%) patients were managed as ambulatory from diagnosis and 54 (7%) patients were discharged to ambulatory pathways. Aside from younger age in patients treated as ambulatory from diagnosis, no significant differences in disease or patient phenotype were observed. The rate of colectomy (15.0% (104/695) vs 13.3% (2/15) vs 13.0% (7/54), respectively, p=0.96) and secondary outcomes were similar among all three cohorts. Stool culture and flexible sigmoidoscopy were less frequently performed in ambulatory cohorts. Forty per cent of patients treated as ambulatory from diagnosis required subsequent hospital admission.ConclusionsIn a post hoc analysis of one of the largest ASUC cohorts collected to date, we report an emerging UK ambulatory practice which challenges treatment paradigms. However, our analysis remains underpowered to detect key outcome measures and further studies exploring clinical and cost-effectiveness as well as patient and physician acceptability are needed.Trial registration numberNCT04411784.
Progression to severe visual impairment and blindness in POAG patients: pace and risk factors—a cohort study using German health claims data
Authors: Nestler Sophia , Kreft Daniel , Doblhammer Gabriele , Guthoff Rudolf F , Frech Stefanie 
Published: January 2022

ObjectiveGlaucoma is a leading cause of severe visual impairment and blindness (SVI/B) worldwide. Hence, it is of utmost importance to explore relevant risk factors and study the pace of progression to SVI/B.Methods and analysisWe used a random sample of 250 000 persons from administrative individual-level health records of the Allgemeine Ortskrankenkassen between 2004 and 2015. We identified 3535 primary open-angle glaucoma (POAG) patients aged 55 and older and followed them for up to 10 years. Monocular and binocular SVI/B were defined by the ICD-10 classifications H54.0 and H54.4. Ophthalmological and chronic disease risk factors were analysed by applying a multivariable Cox proportional hazard model.ResultsThe risk of SVI/B in POAG patients was significantly increased by the presence of specific additional eye diseases such as secondary glaucoma (HR: 3.08, p<0.001), retinal vascular occlusion (HR: 3.00, p<0.001) or age-related macular degeneration (AMD) (HR: 2.26, p<0.001). The risk was highest in the first 2 years after the POAG diagnosis and significantly decreased after the fifth year (HR: 0.36, p=0.002). Ocular injuries, other ocular diseases, non-ophthalmological comorbidities, and age and sex had no significant influence (p>0.05).ConclusionAlthough progression to SVI/B is relatively rare in POAG patients in Germany, one must be aware of additional risk factors, such as secondary glaucoma, retinal vascular occlusion and AMD. Regular ophthalmological examinations help prevent the progression of SVI/B, especially in the first years after the POAG diagnosis. Specific, targeted, and timely treatments for the other eye diseases could help prevent or delay SVI/B.
Improving annual albuminuria testing for individuals with diabetes
Authors: Kam Sharon , Angaramo Santiago , Antoun Jacqueline , Bhatta Manasa R , Bonds Pauleatha Diggs , Cadar Adrian G , Chukwuma Valentine U , Donegan Patrick J , Feldman Zachary , Grusky Alan Z , Gupta Veerain K , Hatcher Jeremy B , Lee Jaclyn , Morales Natalia G , Vrana Erin N , Wessinger Bronson C , Zhang Michael Z , Fowler Michael J , Hendrickson Chase D 
Published: January 2022

BackgroundAnnual albuminuria screening detects the early stages of nephropathy in individuals with diabetes. Because early detection of albuminuria allows for interventions that lower the risk of developing chronic kidney disease, guidelines recommend annual testing for all individuals with type 2 diabetes mellitus and for those with type 1 diabetes for at least 5 years. However, at the Eskind Diabetes Clinic at the Vanderbilt University Medical Center, testing occurred less frequently than desired.MethodsA quality improvement team first analysed the clinic’s processes, identifying the lack of a systematic approach to testing as the likely cause for the low rate. The team then implemented two successive interventions in a pilot of patients seen by nurse practitioners in the clinic. In the first intervention, staff used a dashboard within the electronic health record while triaging each patient, pending an albuminuria order if testing had not been done within the past year. In the second intervention, clinic leadership sent daily reminders to the triage staff. A statistical process control chart tracked monthly testing rates.ResultsAfter 6 months, annual albuminuria testing increased from a baseline of 69% to 82%, with multiple special-cause signals in the control chart.ConclusionsThis project demonstrates that a series of simple interventions can significantly impact annual albuminuria testing. This project’s success likely hinged on using an existing workflow to systematically determine if a patient was due for testing and prompting the provider to sign a pended order for an albuminuria test. Other diabetes/endocrinology and primary care clinics can likely implement a similar process and so improve testing rates in other settings. When coupled with appropriate interventions to reduce the development of chronic kidney disease, such interventions would improve patient outcomes, in addition to better adhering to an established quality metric.
System approach to prevent lost studies and improve radiology report turnaround time
Authors: Schick Jacob , Petscavage-Thomas Jonelle M 
Published: January 2022

PurposeOn our picture archiving and communication system worklist, there was no way to differentiate body imaging (BI) from musculoskeletal (MSK) MR pelvis examinations. They were listed on only the BI worklist. This resulted in ‘lost’ MSK MR pelvis studies with high report turnaround time (TAT). Some exams had preliminary reports with substantiative changes made days later when found. The goals of this project were to create a solution to prevent ‘lost’ exams and improve TAT.MethodsA report of 3 months of MR pelvis studies was reviewed to determine time to first view by MSK radiologists, time of completion, time of preliminary report and time of final signature. Mean TAT was calculated and exams with delays in reporting resident misinterpretation recorded.An MSK reserve flag was created for the BI radiologists to use when they found an MSK study on their worklist. The flag moved them onto the MSK reserve worklist. A second intervention included technologists placing the reserve on examination completion. After this, another 3 months of data was analysed.ResultsThere was a significant improvement (p=0.0018) in time to view by MSK from preintervention mean of 1125 min (n=107) to postintervention mean of 526 min (n=127). There was also a significant improvement (p=0.0033) in time to view inpatient and Emergency department cases from 927 min to 357 min. Time from study completion to final signature also improved from a mean of 1764 min to 838 min, though not statistically significant (p=0.08). There were five cases of delay in reporting resident misinterpretation preintervention and none postintervention.ConclusionOur intervention shows the importance of modifying human and informatics factors to solve a patient safety issue.Introduction