bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the statistical nature of fatigue crack-growth through Monte Carlo simulations and experimental data
Authors: Giannella V. 
Published: January 2022

Abstract
Understanding factors that contribute to scatter in crack-growth rates data is fundamental to reduce risk of unexpected structural failures. This document discusses the statistical nature of material scattering observed in fatigue crack propagation tests through a comparison between Monte Carlo simulations and experimental test data. The case study consists of constant amplitude tests on central cracked 2024-T3 aluminium alloy plate specimens loaded in pure Mode-I with stress ratio R equals to 0.2. It was found that results of simulations matched the experimental fatigue lives in terms of both mean value and dispersion around it. Based on these outcomes, the crack-growth behaviour can be described in a statistical manner with the expectation to reduce the inaccuracy present in life predictions.
Implementation of the Peak Stress Method for the automated FEM-assisted design of welded joints subjected to constant amplitude multiaxial fatigue loads
Authors: Visentin A , Campagnolo A , Sacchet F , Meneghetti G 
Published: January 2022

Abstract
The Peak Stress Method (PSM) is a local approach to the fatigue strength assessment of welded structures. Starting from FE-calculated opening, in-plane shear and out-of-plane shear peak stresses at the weld toe and weld root, the PSM defines an equivalent peak stress for estimating the fatigue failure location and fatigue life of welded structures, in compliance with properly defined design curves. An interactive tool has been developed in Ansys® Mechanical to automate all calculation tasks required to apply the PSM to generic welded structures. The developed application allows to identify and analyse all weld toe and weld root lines of the structure in a full-automated way, performing fatigue life estimation on each analysed node. Finally, fatigue life results can be visualized directly on the model’s geometry through dedicated contour plots. In this work, some joint geometries taken from the literature and related to steel welded joints subjected to multiaxial fatigue loads are re-analysed taking advantage of two design procedures: (i) manual application of the PSM, (ii) automated implementation of the PSM. Taking advantage of the tool developed in Ansys®, a remarkable reduction in analysis time and effort can be achieved, with respect to manual PSM analyses.
A semi-analytical method for the calculation of double-ellipsoidal heat source parameters in welding simulation
Authors: Trupiano S , Belardi V G , Fanelli P , Gaetani L , Vivio F 
Published: January 2022

Abstract
Structural integrity assessment of welded components requires the determination of residual stress and deformations induced by the welding process. The implementation of both a numerical static mechanical analysis and a thermal transient analysis is needed in order to accurately determine stress and strain fields. The most faithful representation of the heat flow provided by the welding torch in thermal simulations is realized with Goldak’s double ellipsoid, especially in case of MIG/MAG and combined TIG-MIG/MAG welding. The correct determination of the temperature trends during the welding process simulation is essential for the subsequent mechanical FEA. In order to obtain the above-mentioned temperature trends, some parameters must be determined ex ante, e.g., the geometrical characteristics of Goldak’s double ellipsoid. Generally, a large number of trial simulations must be performed in order to define these parameters. However, manual fitting is often complicated. To overcome such difficulties, in this work, it is reported a combined analytical and numerical method to determine the parameters using the genetic algorithm NSGA-II. First-attempt parameters are obtained through the solution of the Fachinotti’s analytical formulation. This first stage requires a restricted set of experimental data, such as weld pool extension and one temperature trend in the proximity of the seam. Afterwards, first-attempt parameters and experimental data are used to determine the final parameters by means of a set of numerical thermal simulations guided through the genetic algorithm optimization. To confirm the good-functioning of the method, a numerical analysis for the simulation of the experimental data and another FE simulation performed with the final results of the method are presented.
Discrete model for 3D motion of helical springs
Authors: De Crescenzo F , Salvini P 
Published: January 2022

Abstract
Large displacements of coiled springs are affected by both contact between coils and geometric non-linearities. The two phenomena also interact with each other and the only technology that efficiently accounts for both is Finite Elements Method (FEM). Such analysis can become very expensive, especially when a great number of elements and contacts are involved, as it is often the case. A discrete 3D model for fast and efficient simulation of non-linear springs is presented. The discrete model is based on equivalent beam theory and each node is associated with a contact region placed on the helix. Thus contact is accounted on its real occurrence and fast non-linear solution procedure is implemented. A study case is presented and comparison with FEM is discussed.
Assessment of the deformation behavior of a tensegrity floor through photogrammetry
Authors: Chiappini G , Coccia M , Rossi M , Marchione F , Munafò P , Scoccia C , Luca C 
Published: January 2022

Abstract
Tensegrity structures are interesting elements that can be used to create innovative building components. In this work, the deformation behavior of a new type of tensegrity floor (patent n. 0001426973) was investigated through image analysis and photogrammetry, using stereoscopic algorithms. The main innovation of the proposed tensegrity floor is the structural cooperation between glass tiles and steel components, obtained using suitable adhesive joints. In order to evaluate the deformation of the floor under different loading conditions a non-contact measurement system was developed and validated on a scale prototype of the floor. The used method is a stereoscopic optical technique based on the grid method, the validation was performed comparing the measured displacement with the one measured in the same floor with linear displacement sensors. The stereoscopic images were processed with Matlab®, furthermore, a combination of interpolation algorithms were employed to generate the full-field map of the displacement. Two configurations of the floor (with and without the adhesive joints) and three loading conditions were investigated. The analysis demonstrates that the adhesive joints produce a reduction of the overall deflection of the floor of about 60%, falling within the admissible values established by Italian building code. The measurement system is reasonably accurate and can be used in future applications where linear transducers cannot be installed.
Dynamic behaviour of a battery pack for agricultural applications
Authors: Mocera F , Martelli S , Costamagna M 
Published: January 2022

AbstractFight and contrast against climate change and global warming can be considered the most important challenge for the next decades. One of the most involved sectors is the one related to the carriage of passengers and goods, and, recently, also the work vehicles too. The agricultural machines and tractors are no exception to this. Indeed, agricultural industry is the second contributor in terms of pollutant emissions. So, research about agricultural machinery is focusing itself about the development of more sustainable propulsion systems such as hybrid or full-electric solutions. One of the most important components of a hybrid or full electric vehicle is the battery pack. The lack of adequate vibration isolation is the main cause of battery pack failure during operation. In the field of the agricultural vehicles, since the maximum speed is quite low and the weight of the various subsystems are high, combined with heavy working cycles, the dynamic analysis of the battery pack focuses on its low frequency behaviour. In this context, this paper focuses the attention on the dynamic behaviour of a battery pack, thought for a plug-in hybrid electric orchard tractor, through simulations obtained taking advantage of FEM and multibody software. In particular, it will be illustrated the dynamic behaviour of the battery pack while the tractor is moving on a bumpy road and when the tractor chassis is subjected to an impulsive load.
Active thermography technique for barrier coatings characterization
Authors: Curà F , Sesana R , Corsaro L , Mantoan R 
Published: January 2022

Abstract
Aim of this paper is to define and set up an experimental procedure, based on active thermography, for the characterization of thermal barrier coatings for industrial applications, above all in aerospace field. The developed procedure is intended to be a fast and reliable method, alternative to the consolidated one described in International Standards as ISO18755 and ISO18555. In particular, this approach consists of a pulsed active thermography, in transmission configuration, obtained by means of a laser excitation. Temperature data processing, according to and adapting Standard procedures, allowed us to determine thermal parameters as conductivity and diffusivity. Obtained results were compared in terms of thermal properties variation with respect to base and coated materials, and in term of different coating procedures. These results were also compared to those available in literature.
Evaluation of the thermomechanical Shape memory polymers in equi-biaxial condition by hydraulic bulge test
Authors: Coccia M , Farotti E , Lattanzi A 
Published: January 2022

Abstract
Shape Memory Polymers (SMPs) are materials capable of changing their primary shape to a secondary shape thanks to the so called Shape Memory Effect (SME) phenomenon. The shape-shifting is achieved through the action of an external stimulus, such as heat, electricity, pH, etc. In this paper, experiments on a thermally actuated thin film of a Shape Memory Thermoplastic Polyurethane (SMPU) were performed to calibrate the parameters of a constitutive model which accounts the rubbery/glassy phase transition mechanism behind the shape memory behaviour. In particular, thermomechanical uniaxial tensile tests have been carried out in order to the Young modulus and Poisson’s ratio above/under glass transition temperature and the fixity/recovery ratio. Additionally, the hydraulic bulge test (HBT) in a thermally controlled loading/unloading cycle was used to study the behaviour of the SME at large strains under equi-biaxial stress state. The corresponding outcomes were, therefore, employed to validate the results of the initial calibration by means of a Finite Element (FE) simulation of the HBT.
Adhesion of viscoelastic media: an assessment of a recent JKR-like solution
Authors: Violano G , Orlando G , Demelio G P , Afferrante L 
Published: January 2022

Abstract
Adhesion of soft compliant solids is irreversible and rate-dependent. As a result, two different paths are observed in loading-unloading adhesion experiments because of dissipation occurring in the unloading phase. An effective surface energy is usually introduced to take account of such dissipation.
Here, by exploiting a recent theoretical solution developed to study the detachment of a rigid sphere from a viscoelastic substrate (Violano et al., 2021), two different approaches are considered to calculate the surface energy. The first approach is based on the phenomenological equation derived by Gent & Schultz (A. N. Gent & J. Schultz, 1972), the latter exploits Persson & Brener theory for viscoelastic crack propagation (B. N. J. Persson & E. A. Brener, 2005).
In both cases, results are observed to be in good agreement with experimental data taken from the literature.
Analysis of the rider’s body movement during the intervention of the Autonomous Emergency Braking system for Motorcycles (MAEB)
Authors: Cassese Giovanni , Lucci Cosimo , Savino Giovanni , Baldanzini Niccolò 
Published: January 2022

Abstract
Among the rider assistance systems for powered-two-wheelers (PTWs) that are currently in the developing stage, autonomous emergency braking (identified by the acronym MAEB - Motorcycle Autonomous Emergency Braking) was shown to be promising to significantly improve the safety of such vehicles. This system, which is already available on passenger cars and trucks (known as AEB), reduces the vehicle speed in the event of a forthcoming collision. The lack of implementation of AEB on standard motorcycles is due to the characteristic capsize instability of PTWs and their complex dynamics, which is, strongly influenced by the motion of the rider. In a recent field-test campaign within the EU funded project “PIONEERS”, tests were conducted with common riders as participants to evaluate the intervention of MAEB in urban riding scenarios. A combined analysis of the data recorded from the vehicle, data related to the movement of the rider’s body measured through an inertial measurement unit and videos recorded during the test, allowed characterizing the different behaviours of the rider’s body in response to the activation of the automatic braking system in straight riding conditions. The results showed that body movement can be used as an indicator of the riders’ ability to control the vehicle under automatic braking conditions. In addition, in tests conducted with 0.5 g automatic decelerations, riders showed to be able to recover to natural riding position within the timeframe of the automatic braking activation event. This study defined an innovative method for evaluating the response of motorcyclists to the braking intervention and provides insights into the applicability of MAEB on standard vehicles.
Unraveling the complex genetic basis of growth in New Zealand silver trevally (Pseudocaranx georgianus)
Authors: Valenza-Troubat Noemie , Montanari Sara , Ritchie Peter , Wellenreuther Maren 
Published: January 2022

AbstractGrowth directly influences production rate and therefore is one of the most important and well-studied traits in animal breeding. However, understanding the genetic basis of growth has been hindered by its typically complex polygenic architecture. Here, we performed quantitative trait locus mapping and genome-wide association studies for 10 growth traits that were observed over 2 years in 1,100 F1 captive-bred trevally (Pseudocaranx georgianus). We constructed the first high-density linkage map for trevally, which included 19,861 single nucleotide polymorphism markers, and discovered 8 quantitative trait loci for height, length, and weight on linkage groups 3, 14, and 18. Using genome-wide association studies, we further identified 113 single nucleotide polymorphism-trait associations, uncovering 10 genetic hot spots involved in growth. Two of the markers found in the genome-wide association studies colocated with the quantitative trait loci previously mentioned, demonstrating that combining quantitative trait locus mapping and genome-wide association studies represents a powerful approach for the identification and validation of loci controlling complex traits. This is the first study of its kind for trevally. Our findings provide important insights into the genetic architecture of growth in this species and supply a basis for fine mapping quantitative trait loci, genomic selection, and further detailed functional analysis of the genes underlying growth in trevally.
Heterogeneity in effective size across the genome: effects on the inverse instantaneous coalescence rate (IICR) and implications for demographic inference under linked selection
Authors: Boitard Simon , Arredondo Armando , Chikhi Lounès , Mazet Olivier 
Published: January 2022

Abstract
The relative contribution of selection and neutrality in shaping species genetic diversity is one of the most central and controversial questions in evolutionary theory. Genomic data provide growing evidence that linked selection, i.e. the modification of genetic diversity at neutral sites through linkage with selected sites, might be pervasive over the genome. Several studies proposed that linked selection could be modeled as first approximation by a local reduction (e.g. purifying selection, selective sweeps) or increase (e.g. balancing selection) of effective population size (Ne). At the genome-wide scale, this leads to variations of Ne from one region to another, reflecting the heterogeneity of selective constraints and recombination rates between regions. We investigate here the consequences of such genomic variations of Ne on the genome-wide distribution of coalescence times. The underlying motivation concerns the impact of linked selection on demographic inference, because the distribution of coalescence times is at the heart of several important demographic inference approaches. Using the concept of inverse instantaneous coalescence rate, we demonstrate that in a panmictic population, linked selection always results in a spurious apparent decrease of Ne along time. Balancing selection has a particularly large effect, even when it concerns a very small part of the genome. We also study more general models including genuine population size changes, population structure or transient selection and find that the effect of linked selection can be significantly reduced by that of population structure. The models and conclusions presented here are also relevant to the study of other biological processes generating apparent variations of Ne along the genome.
Small RNA populations reflect the complex dialogue established between heterograft partners in grapevine
Authors: Rubio Bernadette , Stammitti Linda , Cookson Sarah Jane , Teyssier Emeline , Gallusci Philippe 
Published: January 2022

Abstract
Grafting is an ancient method that has been intensively used for the clonal propagation of vegetables and woody trees. Despite its importance in agriculture the physiological and molecular mechanisms underlying phenotypic changes of plants following grafting are still poorly understood. In the present study, we analyse the populations of small RNAs in homo and heterografts and take advantage of the sequence differences in the genomes of heterograft partners to analyse the possible exchange of small RNAs. We demonstrate that the type of grafting per se dramatically influences the small RNA populations independently of genotypes but also show genotype specific effects. In addition, we demonstrate that bilateral exchanges of small RNAs, mainly short interfering RNAs, may occur in heterograft with the preferential transfer of small RNAs from the scion to the rootstock. Altogether, the results suggest that small RNAs may have an important role in the phenotype modifications observed in heterografts.
Intrapuparial Development and Age Estimation of Calliphora grahami (Diptera: Calliphoridae) for Postmortem Interval Estimation
Authors: Wang Yinghui , Hou Yiding , Wang Man , Wang Yu , Xu Wang , Zhang Yanan , Wang Jiangfeng 
Published: January 2022

Abstract
Calliphora grahami (Aldrich, 1930) (Diptera: calliphoridae) is a forensically important blow fly that is widely distributed across Asia, North America, Russia, and Mexico. Calliphora grahami is frequently found on corpses during the spring, autumn, and winter seasons. It is among the early colonizers of cadavers during the cold season, and sometimes, the only necrophagous blow fly on cadavers. Therefore, this species is of forensic significance, although very few studies have explored the application of its intrapuparial age for PMI estimation. This study aimed to examine the intrapuparial development of C. grahami and establish a method for estimating its intrapuparial age. Herein, the C. grahami puparia were studied under six different temperatures (13, 16, 19, 22, 25, and 28°C) for the intrapuparial age estimation, and a total of 5776 puparia were sampled. The morphological changes were divided into 11 stages based on the 1) development of legs and wings, 2) differentiation of the head, thorax, and abdomen, 3) growth and color of the bristles, and 4) color changes of the compound eyes. The corresponding time of each stage was determined. Moreover, the observation and classification of individual morphological features, including compound eyes, antennae, mouthparts, thorax, abdomen, legs, and wings was used to improve the precision of intrapuparial age estimation. The findings of this study provide important information on the use of C. grahami intrapuparia to estimate the minimum postmortem interval (PMImin).
Kingdom-Wide Analysis of Fungal Protein-Coding and tRNA Genes Reveals Conserved Patterns of Adaptive Evolution
Authors: Wint Rhondene , Salamov Asaf , Grigoriev Igor V 
Published: January 2022

Abstract
Protein-coding genes evolved codon usage bias due to the combined but uneven effects of adaptive and nonadaptive influences. Studies in model fungi agree on codon usage bias as an adaptation for fine-tuning gene expression levels; however, such knowledge is lacking for most other fungi. Our comparative genomics analysis of over 450 species supports codon usage and transfer RNAs (tRNAs) as coadapted for translation speed and this is most likely a realization of convergent evolution. Rather than drift, phylogenetic reconstruction inferred adaptive radiation as the best explanation for the variation of interspecific codon usage bias. Although the phylogenetic signals for individual codon and tRNAs frequencies are lower than expected by genetic drift, we found remarkable conservation of highly expressed genes being codon optimized for translation by the most abundant tRNAs, especially by inosine-modified tRNAs. As an application, we present a sequence-to-expression neural network that uses codons to reliably predict highly expressed transcripts. The kingdom Fungi, with over a million species, includes many key players in various ecosystems and good targets for biotechnology. Collectively, our results have implications for better understanding the evolutionary success of fungi, as well as informing the biosynthetic manipulation of fungal genes.