Fold Lines Research Articles

Effective Press Folding Line Process as Producing Smart Intersection in Square Steel Pipe Structures by Using Crushed Cross Section Compactly

As a cross section of square steel pipe is crushed, the upper plate and the lower plate deform inward, and the side plates deform outward from the original square cross section shape. When the press folding line process as deformation induction is applied, the upper plate and the lower plate keep flat, and the side plates are compactly folded inward. This deformation pattern is safe without causing any harm to the surrounding area, and makes it possible to improve impact energy absorption performance by folding side plates as overlapping. Moreover, square steel pipe structures include places as pipes intersect and places to avoid interference with other parts (piping, wiring, fork claws, etc.). In such cases, the current method is to create an opening by cutting off. At that time, the structural strength will decrease, so reinforcing materials are often installed as a countermeasure. On the other hand, if the opening is processed by laterally impact crushing using the press folding line process proposed in this paper, a crushed part will remain, suppressing the decrease in structural strength, and this can be handled without adding reinforcing material to be a smart intersection. This paper shows the findings based on experimental data, FEM (Finite Element Method) results on processing conditions for inward deforming side plates of square steel pipes and evaluation of impact energy absorption performance in laterally impact crushing.

Reverse and antegrade vector thread lifting techniques: Correcting nasolabial and marionette lines.

This study evaluates the efficacy of reverse and antegrade thread lifting vectors in conjunction with thread selection for correcting nasolabial folds and marionette lines, aiming to enhance treatment precision and effectiveness. Three female patients aged 43, 48, and 53, presenting with primary concerns regarding nasolabial folds, underwent distinct treatment regimens utilizing various types of threads and vectors. Additionally, video demonstrations were recorded to showcase the procedural techniques employed in each case. The outcomes of the thread lifting procedures demonstrated significant improvements in the correction of the nasolabial fold and marionette line. Innovative thread insertion techniques involve entry points above the zygomatic arch and threading toward the temple hairline for lateral face lifting. These utilize barbs to pull skin and underlying tissues. The reversal technique involves inserting threads in a criss-cross pattern, forming a fibrous structure that may prolong the duration of results. Various thread combinations, considering factors such as composition, thickness, and barb size, provide customized procedures. This research introduces clinical applications, including temple area hairline lifting for nasolabial fold and marionette line correction, reverse vectors targeting nasolabial folds and marionette lines, and antegrade approaches from the lateral side.

Developable forming of high-strength corrugated sheet metal

The classical theory of folded developables suggests that curved crease folding can be applied to sheet metal of high strength to manufacture parts with complex geometries. However, its application has been limited to sheet metals with low strength and requires grooving or perforation of the material at the fold lines. Applying the geometrical concept otherwise remains unexplored despite its potential in sheet metal-intensive industries like automotive, transportation, and construction. The current study introduces a novel sheet metal forming technique called developable forming. The theory of folded developables is applied to design a die tool for flange drawing a developable-shaped steel sheet. A developable connection is produced from high-strength material without resorting to thickness accommodation techniques. Experimental findings establish that the novel process does not follow the premises of the theory of folded developables. New shape effects are observed and the terms curving and coning are introduced to describe these. Additionally, significant redundant strains are identified in the flange, highlighting the different deformation modes in the developable forming process. A higher formability is achieved for a material with limited uniaxial elongation highlighting the need for further investigation on the mechanisms involved in the novel process.

A Comprehensive Assessment of Soft-tissue Sagging after Zygoma Reduction Surgery through Artificial Intelligence Analysis.

Overdevelopment of zygomatic bones often results in protrusion and flaring of the midfacial region. This makes the face appear squarer than the more favorable oval shape. Therefore, zygoma reduction surgery has become a commonly performed procedure in patients seeking to obtain an ideal facial shape. Facial soft-tissue ptosis is one of the main complications of zygoma reduction surgery. Previously, the evaluation of cheek soft-tissue ptosis was subjectively based on patients and surgeons. Our study aimed to provide an objective evaluation of soft-tissue sagging in the cheek region after zygoma reduction surgery using artificial intelligence (AI). We used AI to evaluate cheek sagging in a series of patients who underwent zygoma reduction surgery. We used four methods: tracking facial landmarks, detecting changes in the cheek curvature, and examining changes in the nasolabial fold and marionette lines. Then, the obtained numerical results were assessed for statistically significant differences using statistical validation methods. Use of AI with the four methods demonstrated no statistically significant differences between the pre- and postsurgery evaluations. AI analysis demonstrated that soft-tissue ptosis did not occur in our series of patients. AI offers objective evaluation for both patients and doctors. Future research could build on this application to examine various influencing factors and develop new tools using machine learning to evaluate and predict the extent of cheek sagging in patients before surgery.

Deployment Simulation of Foldable Membranes Using Absolute Nodal Coordinate Formulation and Validation

It has become a trend to use foldable membranes to construct large spacecraft structures such as solar sails, antennas, and drag sails with the advantages of being lightweight and having high packing efficiency. To enhance the existing numerical simulation of membrane deployment, the nonlinear behavior of the crease is finely described based on experiments and integrated into the numerical model via the principle of virtual work. Specifically, a foldable membrane is modeled as a multibody system (MBS) based on the absolute nodal coordinate formulation (ANCF), where the flexible facet is meshed with both ANCF triangular and quadrilateral thin shell elements and the crease is treated as a virtual torsional spring with special constraints along the fold line. The MBS modeling method is validated via the deployment experiment of a Z-folding membrane. The deployment of a four-unit Miura-ori membrane is further analyzed to show the capability of the approach in modeling foldable membranes with complicated configurations. Good agreement is obtained on the membrane-deformed configurations between the simulation and experiment. Additionally, the driving force at the corners is obtained. This research is expected to provide a more accurate simulation to facilitate the design and optimization of the space deployable membrane structure.

First Report of Kiwifruit Root Rot Caused by Globisporangium spinosum in China.

Kiwifruit is widely cultivated for its high vitamin C content and nutritional value. In January 2022, root rot symptoms were found in about 30% of Actinidia chinensis cv. Jinyan plants grafted on A. deliciosa rootstocks in an orchard located in Sanming (26.32°N, 117.23°E), Fujian Province of China. The affected plants appeared stunted, with brown and decaying roots, some of which were covered with white hyphae. To isolate the pathogen, the surfaces of typical symptomatic roots were sterilized for 30 s using 75% ethanol, followed by four rinses in sterile water, placing on potato dextrose agar (PDA), and incubating away from light at 25°C for 7 days. 16 Globisporangium-like isolates were obtained through hyphal tip isolation, displaying a milky-white appearance with irregular protuberances on the surface, and yellow-white backs with radial fold lines. The isolates were then cultured on corn meal agar for 5 days at 25°C in dark for morphological characteristics. Under microscope, the hyphae appeared as long strips without septa and 4.1 to 8.2 µm wide (average 6.7 µm), containing irregularly sized spherical droplets. Both terminal and intercalary hyphae swellings were observed; these appeared either spherical or subspherical, with some having projections. Their dimensions were 12.3 to 27.6 µm (average 17.3 µm). The oospores were mostly spherical, either plerotic or aplerotic, 11.8 to 22.3 µm wide (average 18.9 µm), with occasional projections. The antheridia were rod-shaped and curved, with one end attached to the oogonia. Amplification of the sequences of internal transcribed spacer (ITS) regions and cytochrome c oxidase subunit I (COI) were conducted using the primers ITS1/ITS4 (White et al. 1990) and OomCoxI-Levlo/OomCoxI-Levup (Robideau et al. 2011), respectively. The sequencing results revealed identical ITS and COI sequences in all 16 isolates. BLASTn analysis of the 969-bp ITS sequence ON202808 showed 99.38-99.59% similarity (965/971bp, 967/971bp) with the KJ162353 and AY598701 sequences from Globisporangium spinosum isolates, while the 700-bp COI sequence ON075783 showed 100% and 99.41% identity (680/680bp, 676/680bp) with the GenBank sequences HQ708835 and HQ708832, respectively, from G. spinosum. Phylogenetic analysis also showed that the obtained isolate (termed MA16) clustered with isolates from G. spinosum on the same evolutionary branch. For pathogenicity testing, four-month-old healthy Jinyan (A. chinensis) plants grown in sterilized media were transferred to sterile petri dishes covered with wet filter paper, and their roots were inoculated with a 5-mm-wide disk of MA16 when cultivated on PDA medium for 5 days. Miliang-1 (A. deliciosa) and Hongyang (A. chinensis) plants were treated similarly. The control groups each included three plants that were inoculated with non-colonized PDA. The plants were kept at 25 °C with a 12-/12-h light/dark cycle for 10 days when the inoculated plants exhibited root rot symptoms similar to those seen in the field, together with rotting and browning of the leaves. The control plants appeared healthy with no symptoms. After re-isolated from infected tissues, the pathogen was verified to be G. spinosum according to its ITS sequence, thus fulfilling the Koch's postulates. Recently, Pythium spinosum has been classified as G. spinosum according to whole-genome sequencing and phylogenomic analysis (Nguyen et al. 2022). Based on the morphological features and pathogenicity results, MA16 was identified as G. spinosum (van der Plaats-Niterink 1981; Huo et al. 2023). This report appears to be the first description of kiwifruit root rots caused by G. spinosum in China, and its identification will assist the development of strategies to counteract the disease.

Analysis of experience in optimizing the operation of an automated production line for folding cardboard boxes

The object of research is an automated system for controlling the bending mechanisms of the folding-gluing line for cardboard packaging products. In the work, the ways of optimization and the development of an automated control system for the bending mechanisms of the folding and gluing line, which makes it possible to fold various structures and standard sizes of cardboard boxes using modern automation tools based on programmable logic controllers, were carried out in the work. A mathematical model has been proposed to describe operations on the folding-gluing line. Based on the model, a methodology has been developed for calculating the parameters of the automated control system for the box folding production line, depending on the technical parameters of the line and the parameters of the boxes to be bent. This will make it possible to choose optimal technological modes of the production process and obtain high quality parameters of cardboard packaging products. To verify the mathematical model of the production line, software has been developed in the Delphi development environment, which was applied with the developed automated production process control system based on a programmable logic controller (PLC) and an operator panel. This produced a number of results, in particular, controlling the speed of the hook bend in proportion to the speed of the line. And also provided an opportunity to increase line speed and, accordingly, production productivity. It has been possible to change the mutual location of system elements, which made it possible to reduce the distance between workpieces and increase the capacity of the line tape by 30 %. The obtained research results were implemented at the production enterprise of typographic products «Dinas» (Zaporizhzhia, Ukraine), which contributed to the improvement and optimization of production processes. Conducting further research will provide an opportunity to expand the proposed methodology for use on all types of folding and gluing lines.

Asthma in patients with the syndrome of undifferentiated dysplasia of connective tissue: peculiarities of the course or mutually aggravating mechanisms?

Aim: To analyse laboratory and biochemical features of the severe persistent course of asthma in patients with undifferentiated connective tissue dysplasia (UCTD) syndrome, and their phenotypic and visceral stigmas of dysembryogenesis. Materials and Methods: We enrolled 60 male patients with asthma, aged from 23 to 62 years (mean age (46.83 ±0.85) years): 30 patients with the background of UCTD, and 30 - without UCTD. We analysed clinical, somatometric, surveying (original questionnaire based on the phenotypic map of Glesby), instrumental (spirography, echocardiography, endoscopy, esophagofibrogastroduodenoscopy) and laboratory (including eosinophilic granulocytes and aldosterone levels) data. Results: Correlations were found in men with UCTD between the number of UCTD markers and rate of earlobe diagonal fold (r=+0.75; р<0.05), asthenic constitution (r=+0.72; р<0.05), easy bruising (r=+0.7; p<0.05) and straight abdominal line hernia (r=+0.52; p<0.05). Average aldosterone serum level in patients with UCTD (176,10 ±11,22) was significantly higher than in those without UCTD (142,77 ±9,43), (p<0.05), as well as average eosinophils levels (1.3 ±0.25 vs. 0.57 ±0.12, p<0.05). In the absolute majority of patients with UCTD (93.3%) asthma onset was confirmed after pneumonia, and their age of asthma manifestation was significantly higher (37.2 ±1.21) than in patients without UCTD (21.4 ±1.13). Also, in patients with UCTD there was a high number of severe exacerbations during the last year (2.7 ±0.12 per year) on the background of high doses of combined inhaled glucocorticosteroids use. Conclusions: Identified "phenotypic profile", clinical and biochemical features of patients with asthma on the background of UCTD syndrome, which determine the severe course and early formation of asthma complications, will further accelerate the diagnosis of this asthma phenotype and improve approaches to the selection of treatment regimens for these patients.

Detrimental Effects of Metal Foil’s Surface Imperfections on Metal Plating/Stripping and Facile Solutions

Rechargeable metal batteries have attracted great interest and are considered one of the most promising high-energy density storage systems. These devices benefit from the large specific volumetric capacities and high specific gravimetric capacities of metal anodes. Foils or sheets are the most common form of anode for metal batteries since they are massively manufactured and readily accessible. But short circuits from dendrites grown on metal foil anodes can dramatically decrease the cycling stability and lead to premature failure of the batteries.Homogeneous metal plating/stripping is the key to avoiding dendrite formation. And the surface uniformity of metal electrodes is crucial for the initial nucleation and growth, which greatly affects the subsequent deposition. Here, we show that manufacturing-induced defects, including surface imperfections such as a roughened surface, orange peel features, microcracks, scratches, or fold lines, and unpolished edges from cutting can all promote local dendrite growth, leading to drastically decreased cycling stability of the demonstrated Zn metal batteries and K metal batteries. Polishing the metal electrodes on both sides and edges is shown to be effective to improve the electrochemical homogeneity of the metal anode and extend the cycling lifespan by over 700% in the demonstrated Zn metal cells. Finally, we demonstrate a simple and rapid surface passivation strategy that drastically increases the tolerance of such defects in Zn metal batteries. Also, we proposed a scalable, easily automated, and facile metallic K manufacturing with robust performance in K metal batteries.Since such imperfections are ubiquitous in commercially available metal foil products. Our results remind researchers about the significant detrimental effects of these very common defects introduced by metal manufacturing and processing, which should be taken into consideration evaluating metal battery performances. Furthermore, we call for research efforts to develop effective strategies that are scalable, easily automated, and cost-effective to increase the tolerance of batteries over such defects, which will be very important for large-scale, cost-effect energy storage hubs.References Pan He and Jiaxing Huang. "Detrimental effects of surface imperfections and unpolished edges on the cycling stability of a zinc foil anode." ACS Energy Letters, 2021,6,1990-1995.Pan He and Jiaxing Huang. "Chemical passivation stabilizes Zn anode." Advanced Materials, 2022, 34, 2109872.Pan He and Yang Xu. "Facile manufacturing potassium metal anode with robust performance". In preparation. Figure 1

Exploring for structurally concealed Carlin-type mineralization: A case study from the northern Shoshone Range, Nevada, USA

This study integrates results from previous studies with new reconnaissance-scale mapping of rock types, structures, and hydrothermal alteration at Goat Ridge and Tenabo to provide a district-scale cross section and palinspastic restoration of an area in Nevada with high potential for Carlin-type mineralization in the footwall of a dismembered thrust fault. Reinterpretation of legacy drill data in light of recent advances in the understanding of Cenozoic normal faulting in the area with the expected stratigraphy of the Roberts Mountains autochthon allows for deciphering whether previous drill holes piercements of faults are the Roberts Mountains thrust or are tilted normal faults that down-dropped the deep-water siliciclastic rocks of Roberts Mountains allochthon onto the coeval carbonate rocks of the Roberts Mountains autochthon. A cross-sectional reconstruction shows that ∼11.1 km (120 %) of extension was accomplished along one set of faults that initiated at 60-70°and tilted 40°E. Previously underappreciated Mesozoic folds are present, which likely formed with horizontal fold hinges. Because of Cenozoic normal faulting and associated tilting, the hinge lines currently plunge at moderate angles and are offset as they step across each crosscutting fault. The anticlinal fold hinges produced the modern exposures of lower plate rocks in the range. The Eocene paleogeologic map that results from a plan-view structural restoration shows that the hinge lines of the original folds trended northwest-southeast in the southern half of the range but turned northward toward the northern end of the range.Mineralization in the range includes silver-dominated polymetallic veins/lodes, weak porphyry-type, Carlin-type, and siliciclastic-hosted gold deposits of uncertain origin. Porphyry-style and silver-dominated polymetallic vein mineralization is associated with ∼39–40 Ma granodiorites, with the silver-dominated polymetallic veins interpreted as the distal veins around weakly mineralized and/or deeply buried porphyry system(s), probably of the quartz monzonitic-granitic porphyry Mo-Cu subclass of porphyry molybdenum deposits. Crosscutting relationships demonstrate that at least one of “upper plate” gold deposits is Eocene, but a Miocene age cannot be ruled out for the other gold deposits.

3D curved-walled same-phase chiral honeycombs with controllable compression-torsion coupling effect via variable cross-section design

Honeycombs are widely-used protective structures with exceptional properties. However, the performance improvement relying on regular configuration optimization and parametric study are relatively limited, because main plastic deformation only concentrates in folding line regions under progressive folding mode. To address this issue, 3D curved-walled same-phase chiral strategy is designed for honeycombs, and their crash performance is studied by experiments, numerical simulations, and theoretical analysis. The proposed honeycombs exhibit approximate progressive folding mode with controllable local compression-torsion coupling effect under out-of-plane loads. Therefore, the shearing energy is obviously increased, and the plastic hinge lines have been prolonged to increase bending energy. According to experimental results, the proposed honeycombs can achieve specific energy absorption SEA and energy absorption efficiency η respectively of 30.92J/g and 73.7 %, which are 14.6 % and 24.9 % larger than traditional honeycomb with same thickness. Moreover, their mean stress is effectively estimated based on plastic hinge analysis, and the contribution of coupling effect on crashworthiness is demonstrated. Furthermore, out-of-plane thickness gradient design can be implemented to further promote the crashworthiness. The proposed honeycomb with thickness gradient of Δt/tave=1.5 displays SEA and η respectively 10.9 % and 23.1 % larger than the non-gradient model under same equivalent density. This study for the first time introduces compression-torsion coupling mechanism into honeycombs, and provides a reference for developing high-performance honeycombs and expanding their potentials.

Image-Based OA-Style Paper Pop-Up Design via Mixed-Integer Programming.

Origami architecture (OA) is a fascinating papercraft that involves only a piece of paper with cuts and folds. Interesting geometric structures 'pop up' when the paper is opened. However, manually designing such a physically valid 2D paper pop-up plan is challenging since fold lines must jointly satisfy hard spatial constraints. Existing works on automatic OA-style paper pop-up design all focused on how to generate a pop-up structure that approximates a given target 3D model. This article presents the first OA-style paper pop-up design framework that takes 2D images instead of 3D models as input. Our work is inspired by the fact that artists often use 2D profiles to guide the design process, thus benefited from the high availability of 2D image resources. Due to the lack of 3D geometry information, we perform novel theoretic analysis to ensure the foldability and stability of the resultant design. Based on a novel graph representation of the paper pop-up plan, we further propose a practical optimization algorithm via mixed-integer programming that jointly optimizes the topology and geometry of the 2D plan. We also allow the user to interactively explore the design space by specifying constraints on fold lines. Finally, we evaluate our framework on various images with interesting 2D shapes. Experiments and comparisons exhibit both the efficacy and efficiency of our framework.

Optimization as generator of structural instability: Koiter’s worst imperfection

This paper is focused on the interaction of local modes in pin-jointed structures, with the aim to present an algorithm for the appraisal of the lowest critical load characterizing the structure under the effect of small imperfections. This interaction phenomenon is framed within Koiter’s theory of elastic instability as a quartic system. First of all, the paper discusses the theoretical results of Koiter’s theorem about the determination of the worst imperfection with respect to the critical load. In doing this, the characterization of the fold lines in the modal space is recalled and used for the purposes of the reformulation of the theorem. Then, a FEM code aimed at the determination of the most dangerous shape of the imperfection, and at performing the related sensitivity analysis, is presented. The basis of the code is a nonlinear model of a 3D rod equipped with a planar flexural deformation, within the context of Eulerian instability. Some numerical results having a practical interest are discussed.

Shear strength evaluation of steel beams with partially corrugated web

This paper introduces a new type of corrugated web beam: the beam with a partially corrugated web (PCW), which presses a steel plate into a vertically rounded rectangular shape. To investigate the shear behavior of this new beam, the experimental tests on the PCW beam and conventional beam were carried out at 4.32, 5.94, and 7.56 m span length with a web thickness of 2.3 and 3.2 mm. The PCW beam has a high shear strength and large deformation capacity, but almost the same bending capacity compared with the conventional one. In shear failure mode, the PCW has an initial local buckling near top and bottom of pressed boundary and shows a global buckling with several diagonal fold lines with increasing load, whereas conventional one shows a single elastic buckling. The moment capacity of PCW agrees well agree with design criteria. When the PCW is considered a sinusoidal corrugated web, the local buckling of Eurocode 3 is almost the same or slightly lower than test results, and the global buckling is higher.

Correction of Primary Multiple Upper Eyelid Folds by Three Mini-Incision Upper Blepharoplasty and Simultaneous Orbital Fat Pad Repositioning in East Asians.

This study aims to assess the feasibility and efficacy of a three mini-incision upper blepharoplasty combined with simultaneous orbital fat pad repositioning for correcting primary multiple upper eyelid folds in East Asians. A retrospective analysis of 75 patients who underwent three mini-incision double-eyelid blepharoplasty in conjunction with orbital fat pad repositioning for the correction of multiple upper eyelid folds between January 2018 and January 2022 was conducted. During the surgery, the lateral extension of the central upper eyelid fat mass was anchored medially to the upper medial eyelid via three small skin incisions. Postoperative follow-up was carried out to evaluate the improvement in multiple upper eyelid folds, and patient satisfaction was measured. The follow-up period ranged from 6 to 36 months, with an average of 12 months. Post-surgery, the multiple fold lines were completely resolved in 71 patients (95%), while relapse occurred in 4 patients (5%). The overall satisfaction rate was 88%. The three mini-incision double-eyelid blepharoplasty combined with simultaneous orbital fat repositioning is an effective method for correcting primary multiple upper eyelid folds. This technique presents a novel alternative for patients with primary multiple eyelid folds, particularly those who are hesitant to undergo a full-incision double-eyelid procedure. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The third generation barbed lifting threads: Added value of hyaluronic acid.

Facial thread lifting is a highly demanded procedure in esthetic clinics worldwide. The aim of this retrospective study is to evaluate the clinical effectiveness and overall patients' satisfaction of a new generation of barbed threads, in which a hyaluronic acid (HA) coat was added to the PLLA/PCL threads and compare the results with PLLA/PCL threads without HA. Twenty patients treated with the PLLA/PCL threads with or without hyaluronic acid (HA) were compared for FaceQ scales: Age appraisal, psychological function, skin satisfaction, satisfaction with facial appearance, appraisal lines of nasolabial folds, satisfaction of lower face, and jaw were compared at baseline, 4 and 12 months post-treatment. Early impact on life and the skin adverse effects were assessed 1 week post-treatment. Finally, patients and two physicians provided the GAIS score at 4 and 12 months and a comparison was made between the two groups. There was a statistically significant improvement in all scales of FaceQ for all included patients at baseline and at 4 and 12 months post-treatment. Importantly, there were less skin-related adverse effects such as skin redness, uneven tone, irregular surface, burning, and itching sensation at a recovery period (1 week post-treatment) in the group receiving HA-containing threads. A notably higher long-term improvement in aging appearance, satisfaction with face appearance, lower jaw and face as well as GAIS was seen in the group treated with HA-containing threads compared to the other treatment arm.

Formed developables - a new class of sheet metal parts

Sheet metal parts are broadly classified as stamped parts versus folded developables. While stamped parts are parts manufactured using conventional sheet metal forming techniques, folded developables are curved developable connections produced by the virtue of the classical theory of folded developables. However, folding is not suitable for parts where material integrity cannot be compromised at the fold lines. In such cases, forming techniques can be used to introduce a distributed curvature and avoid material self-intersection at the curved fold axis. This paper combines the two genres to introduce a third class of parts called the formed developables. A developable shaped, thin sheet metal of very high strength and reasonable inextensibility is formed by flange drawing over a die radius. The die tool establishes the required curved bend axis, and the die radius is small enough to introduce a distributed curvature. A developable connection is successfully formed where the two connected corrugations are mirror images of each other. While no tearing or wrinkling is observed, experimental strain measurements highlight significant surface strains in the transverse direction while marginal stretching strains are observed in the forming direction. A trend of equal and opposite transverse strains strongly suggests that the major deformation in this geometrical process, and in-turn the shape of the final part, is driven by the involved geometrical parameters.

Skin and soft tissue modeling and its impact on apparel modeling

Rigid body avatars do not fully define the complex interaction between human and body-worn product (humanoid-to-coveroid). Skin and soft tissue modeling to create more realistic 3D humanoid body models are needed. We considered if humanoid split lines relevant to pattern-engineering practice can be related to biodynamic and fold lines of the skin. Changes in skin and tissue are expected, depending on the dermis, the effects of movement, and the effects of coveroid pressure. The physiological functions of the skin may be assigned mechanical parameters for dynamic study utilizing biodynamic excisional skin tension (BEST) lines, main folding lines (MFL) with Langer’s lines. Critical to such study is the connecting of the skin to the rig (humanoid virtual skeleton). The use of stable (skeletal feature points related to both the virtual skeleton and apparel block patterns) and morphological (skin feature points identifying areas of morphological variation and dynamic study) landmarks for connecting the skin to rig was analyzed. We utilized these landmarks to drive lines as BEST, MFL and Langer’s lines for the mapping of skin deformations. Initial findings suggest the use of stable and morphological landmarks could have profoundly positive effects throughout the entire digital product creation (DPC) production pipeline and should be further explored &amp; are important in developing standard topology practice.

Large impact of small vertex cuts on the mechanics of origami bellows

For origami structures, perforating or cutting slits along creases is an effective method to define fold lines and alleviate stress concentrations at vertices. In this letter we show numerically and experimentally that for non-rigid-foldable origami bellows (e.g. Miura-ori, Kresling patterns) the introduction of small cut-outs at the vertices results in up to an order of magnitude reduction of the bellows’ stiffness under axial compression. Further, the cut-outs at vertices impact the nonlinear response, e.g. the position and magnitude of a force limit point and presence of bistable configurations. As the origami bellows are not rigid foldable, an axial compression will necessarily result in facet deformations; the small cut-outs at the vertices are found to provide an unexpectedly large stress alleviation, resulting in disproportionate changes in mechanical properties of the bellows. In order to accurately model the mechanics of origami bellows, such manufacturing details must therefore be captured accurately. Lastly, introducing vertex cut-outs can be offered as a novel approach to tailoring the stiffness of non-rigid foldable origami structures.

Assessment of paperboard large deformation at fold using digital image correlation technique

Abstract For coated paperboard with large deformations, there is limited knowledge on the mechanisms that lead to coating damage and on the key properties that affect damage. Large deformations produce complex non-linear mechanical responses which often result in significant internal damage. The objective of this work was to establish methods to directly measure local deformation at a fold using a stereo digital image correlation (DIC) technique and a folding device designed in-house. This allowed monitoring of deformation from both cross-section and surface views, from which curvature and strain could be analyzed. This approach allowed observation and quantification of the initiation and propagation of damage. Testing showed that elastic estimation of deformation is valid only at very small curvatures but is still qualitatively useful. It was found that CD fold line shows a lower strain than MD fold line at a given curvature, but it ultimately reaches a higher level of surface strain. Additionally, localized maximum surface strain was shown to correlate better with surface damage at fold than the average surface strain. Furthermore, the introduced discontinuity index can provide a useful tool to compare surface damage at fold even for paperboard samples with different thicknesses.