Rupture Force Research Articles

Engineering an artificial catch bond using mechanical anisotropy

Catch bonds are a rare class of protein-protein interactions where the bond lifetime increases under an external pulling force. Here, we report how modification of anchor geometry generates catch bonding behavior for the mechanostable Dockerin G:Cohesin E (DocG:CohE) adhesion complex found on human gut bacteria. Using AFM single-molecule force spectroscopy in combination with bioorthogonal click chemistry, we mechanically dissociate the complex using five precisely controlled anchor geometries. When tension is applied between residue #13 on CohE and the N-terminus of DocG, the complex behaves as a two-state catch bond, while in all other tested pulling geometries, including the native configuration, it behaves as a slip bond. We use a kinetic Monte Carlo model with experimentally derived parameters to simulate rupture force and lifetime distributions, achieving strong agreement with experiments. Single-molecule FRET measurements further demonstrate that the complex does not exhibit dual binding mode behavior at equilibrium but unbinds along multiple pathways under force. Together, these results show how mechanical anisotropy and anchor point selection can be used to engineer artificial catch bonds.

Determination of single-molecule loading rate during mechanotransduction in cell adhesion.

Cells connect with their environment through surface receptors and use physical tension in receptor-ligand bonds for various cellular processes. Single-molecule techniques have revealed bond strength by measuring "rupture force," but it has long been recognized that rupture force is dependent on loading rate-how quickly force is ramped up. Thus, the physiological loading rate needs to be measured to reveal the mechanical strength of individual bonds in their functional context. We have developed an overstretching tension sensor (OTS) to allow more accurate force measurement in physiological conditions with single-molecule detection sensitivity even in mechanically active regions. We used serially connected OTSs to show that the integrin loading rate ranged from 0.5 to 4 piconewtons per second and was about three times higher in leukocytes than in epithelial cells.

Mechanical strengthening of cell-cell adhesion during mouse embryo compaction

Compaction is the first morphogenetic movement of the eutherian mammals and involves a developmentally regulated adhesion process. Previous studies investigated cellular and mechanical aspects of compaction. During mouse and human compaction, cells spread onto each other as a result of a contractility-mediated increase in surface tension pulling at the edges of their cell-cell contacts. However, how compaction may affect the mechanical stability of cell-cell contacts remains unknown. Here, we used a dual pipette aspiration assay on cell doublets to quantitatively analyze the mechanical stability of compacting mouse embryos. We measured increased mechanical stability of contacts with rupture forces growing from 40 to 70 nN, which was highly correlated with cell-cell contact expansion. Analyzing the dynamic molecular reorganization of cell-cell contacts, we find minimal recruitment of the cell-cell adhesion molecule Cdh1 (also known as E-cadherin) to contacts but we observe its reorganization into a peripheral adhesive ring. However, this reorganization is not associated with increased effective bond density, contrary to previous reports in other adhesive systems. Using genetics, we reduce the levels of Cdh1 or replace it with a chimeric adhesion molecule composed of the extracellular domain of Cdh1 and the intracellular domain of Cdh2 (also known as N-cadherin). We find that reducing the levels of Cdh1 impairs the mechanical stability of cell-cell contacts due to reduced contact growth, which nevertheless show higher effective bond density than wild-type contacts of similar size. On the other hand, chimeric adhesion molecules cannot form large or strong contacts indicating that the intracellular domain of Cdh2 is unable to reorganize contacts and/or is mechanically weaker than the one of Cdh1 in mouse embryos. Together, we find that mouse embryo compaction mechanically strengthens cell-cell adhesion via the expansion of Cdh1 adhesive rings that maintain pre-compaction levels of effective bond density.

Polyamidoamine epichlorohydrin (PAAE) wet-strength agent: Generations, application, performance, and recyclability in paperboard and linerboard

Polyamidoamine epichlorohydrin (PAAE) is the preeminent permanent wet strength additive used in papermaking. Wet strength additives are used to improve paper resistance to a rupture force in wet environments. The invention of PAAE in 1957 was an innovation, as it improved paper properties by giving superior wet strength in humid or wet conditions. It was rapidly adopted by the industry. Despite PAAE’s long history, the mechanism of PAAE interaction with fiber has not been fully understood. Therefore, fundamental understanding of PAAE mechanism needs to be investigated to improve its utilization in making sustainable paper products. These areas include an understanding of repulping methods and optimal PAAE dosages for better cost and performance. This paper investigates different generations of PAAE, the application method, and its impact on paper recyclability. Three generations of PAAE are currently on the market with at least two newer iterations under development. Critical application parameters that need to be understood include determination of the bonding mechanism, optimal dosage, and retention parameters. The main drawback of PAAE application is it makes paper recycling difficult. Several repulping methods are proposed for better recyclability and sustainability in the papermaking process.

Comparative gelation characteristics of carrageenan via rheological and optical techniques: Glazing gels with different sweeteners

Glazing gels used as decorative gels are most often applied by hot spraying of solutions based on fast-setting hydrocolloids. The formation of a non-sticky gel at room conditions is crucial for their use. Gel formation and gel melting of carrageenan-based glazing gels (CGGs) with various sweeteners (trehalose, erythritol with stevia, maltitol, oligofructose, and nutriose with sucralose and acesulfame) were monitored during cooling-heating cycles using both the oscillatory rheology and the multispeckle diffusing wave spectroscopy (MS-DWS). In addition, rheological properties (shear viscosity of sols, the viscoelastic properties of gels, gel breaking strain) and texture properties (gel strength, elasticity and rupture force) were evaluated. The 12% addition of sweeteners resulted in a significant increase in gelling and melting temperatures by 2–6 °C compared to the sugar-free control sample (42 °C and 57 °C, resp.). MS-DWS, as opposed to oscillatory rheology, allowed determining of the characteristic temperatures at the beginning, middle and end of the phase transitions. The rheology gelling temperatures correlated best with the end of the gelation process, while the melting temperatures corresponded to the middle point temperature of the MS-DWS. Mechanical properties showed CGGs create a continuous gel structure characterized by a viscoelastic solid with comparable hardness and strength at small deformation, and greater elasticity compared to the sugar-free control sample. CGGs containing small molecule sweeteners formed stronger gels against rupture at large deformation than those ones with macromolecular structure. Sols of all CGGs were clear dispersions at 70 °C with Newtonian fluids characteristics and low viscosity (in the range of 9.3–10.9 mPas). These findings prove CGGs with various sugar-replaced sweeteners could be applied by hot spraying method and indicate how MS-DWS can be used to monitor gelation processes.

Correlations between a Friabilin Content Indicator and Selected Physicochemical and Mechanical Properties of Wheat Grain for Processing Suitability Assessment

A new approach to determining the friabilin content of wheat grain was proposed. Electropherograms were taken, and the intensity of the friabilin bands was compared in the analyzed wheat cultivars and the cv. Chinese Spring. The friabilin content indicator was calculated in the grain of 17 common wheat cultivars, which differed mostly in their crude protein content and hardness index (HI). The basic properties of the kernels were measured in each wheat cultivar, and the correlations between the measured parameters and the friabilin content indicator were determined. In the analyzed wheat cultivars, the friabilin content indicator ranged from around 0.21 to around 0.77. This indicator was significantly correlated with the kernel length, thickness, mass, vitreousness, HI, and rupture force. The strongest correlation was observed between the friabilin content indicator and kernel length. An increase in the mean kernel length from around 5.4 mm to around 8.0 mm decreased the friabilin content indicator by approximately 51%. After the mean kernel length had been calculated in a given wheat cultivar, a certain value of the friabilin content indicator could be ascribed to this cultivar, and the energy consumption during grain grinding or milling could be partly predicted. In the group of analyzed wheat cultivars, the process of grain grinding would be the most energy-intensive in the cvs. Ceres, SMH200, and SMH214 and the least energy-intensive in the cvs. Chinese Spring, Julius, and Askalon.

Cannabidiol-loaded microparticles embedded in a porous hydrogel matrix for biomedical applications

In this study, poly (lactic-co-glycolic acid) (PLGA) microparticles loaded with cannabidiol (CBD) were synthesized (PLGA@CBD microparticles) and embedded up to 10 wt% in a chondroitin sulfate/polyvinyl alcohol hydrogel matrix. In vitro chemical, physical, and biological assays were carried out to validate the potential use of the modified hydrogels as biomaterials. The microparticles had spherical morphology and a narrow range of size distribution. CBD encapsulation efficiency was around 52%, loading was approximately 50%. Microparticle addition to the hydrogels caused minor changes in their morphology, FTIR and thermal analyses confirmed these changes. Swelling degree and total porosity were reduced in the presence of microparticles, but similar hydrophilic and degradation in phosphate buffer solution behaviors were observed by all hydrogels. Rupture force and maximum strain at rupture were higher in the modified hydrogels, whereas modulus of elasticity was similar across all materials. Viability of primary human dental pulp cells up to 21 days was generally not influenced by the addition of PLGA@CBD microparticles. The control hydrogel showed no antimicrobial activity against Staphylococcus aureus, whereas hydrogels with 5% and 10% PLGA@CBD microparticles showed inhibition zones. In conclusion, the PLGA@CBD microparticles were fabricated and successfully embedded in a hydrogel matrix. Despite the hydrophobic nature of CBD, the physicochemical and morphological properties were generally similar for the hydrogels with and without the CBD-loaded microparticles. The data reported in this study suggested that this original biomaterial loaded with CBD oil has characteristics that could enable it to be used as a scaffold for tissue/cellular regeneration.Graphical

A Novel Tendon Injury Model, Induced by Collagenase Administration Combined with a Thermo-Responsive Hydrogel in Rats, Reproduces the Pathogenesis of Human Degenerative Tendinopathy.

Patellar tendinopathy is a common clinical problem, but its underlying pathophysiology remains poorly understood, primarily due to the absence of a representative experimental model. The most widely used method to generate such a model is collagenase injection, although this method possesses limitations. We developed an optimized rat model of patellar tendinopathy via the ultrasound-guided injection of collagenase mixed with a thermo-responsive Pluronic hydrogel into the patellar tendon of sixty male Wistar rats. All analyses were carried out at 3, 7, 14, 30, and 60 days post-injury. We confirmed that our rat model reproduced the pathophysiology observed in human patients through analyses of ultrasonography, histology, immunofluorescence, and biomechanical parameters. Tendons that were injured by the injection of the collagenase-Pluronic mixture exhibited a significant increase in the cross-sectional area (p < 0.01), a high degree of tissue disorganization and hypercellularity, significantly strong neovascularization (p < 0.01), important changes in the levels of types I and III collagen expression, and the organization and presence of intra-tendinous calcifications. Decreases in the maximum rupture force and stiffness were also observed. These results demonstrate that our model replicates the key features observed in human patellar tendinopathy. Collagenase is evenly distributed, as the Pluronic hydrogel prevents its leakage and thus, damage to surrounding tissues. Therefore, this model is valuable for testing new treatments for patellar tendinopathy.

Virus-like Particles Armored by an Endoskeleton.

Many virus-like particles (VLPs) have good chemical, thermal, and mechanical stabilities compared to those of other biologics. However, their stability needs to be improved for the commercialization and use in translation of VLP-based materials. We developed an endoskeleton-armored strategy for enhancing VLP stability. Specifically, the VLPs of physalis mottle virus (PhMV) and Qβ were used to demonstrate this concept. We built an internal polymer "backbone" using a maleimide-PEG15-maleimide cross-linker to covalently interlink viral coat proteins inside the capsid cavity, while the native VLPs are held together by only noncovalent bonding between subunits. Endoskeleton-armored VLPs exhibited significantly improved thermal stability (95 °C for 15 min), increased resistance to denaturants (i.e., surfactants, pHs, chemical denaturants, and organic solvents), and enhanced mechanical performance. Single-molecule force spectroscopy demonstrated a 6-fold increase in rupture distance and a 1.9-fold increase in rupture force of endoskeleton-armored PhMV. Overall, this endoskeleton-armored strategy provides more opportunities for the development and applications of materials.

Chemical, physical, and sensory properties of nixtamalized oat tortillas

AbstractBackground and ObjectivesWhile alkaline nixtamalization has historically been used for corn, this process may have application in other cereals. Drawbacks to wider use include the lengthy steep time, as well as the volume of alkaline wastewater produced. This study evaluated a novel, waste‐effluent‐free nixtamalization process for oat (Avena sativa) masa, and compared properties of oat masa and tortillas prepared with 1%, 1.5%, and 2% lime, with and without steeping.FindingsA minimal‐water‐addition, 45‐min simmering process, without steeping, was effluent‐free, and produced oat tortillas comparable to those produced using a traditional overnight steep. The pH increased significantly with increasing lime content (r = .982). Consumer overall‐liking scores did not significantly differ across treatments, though appearance scores were significantly higher for 2% lime samples (p &lt; .05), which were significantly darker and more yellow, based on L* and b* values. Masa adhesiveness means ranged from 1.49 to 1.52 N, with no significant differences between the no‐steep treatments. Higher lime addition (1.5%–2%) in the no‐steep process significantly improved tortilla flexibility, based on extensibility and rollability scores, though tortilla rupture force did not vary significantly across treatments. Tortilla rollability scores at 3‐days were lowest ( = 1.1 + 0.31, indicating less cracking) for the 1.5%–2% lime no‐steep treatments, which were significantly better than the steeped treatment ( = 3.7 + 0.48). Consumers rated the steeped sample as significantly less flexible. B‐vitamins were negatively impacted by increasing lime, while calcium increased significantly with lime addition.ConclusionsThe no‐steep, effluent‐free nixtamalization process produced oat tortillas with good masa and tortilla texture, which were not significantly different in consumer liking than tortillas produced via a traditional process.Significance and NoveltyThis research suggests nixtamalization can be applied to other grains in a shorter, environmentally friendly process, with broader commercial applicability.

Stochastic finite element modeling of heterogeneities in massive concrete and reinforced concrete structures

AbstractThe lifespan of a reinforced concrete (RC) structure can be greatly influenced by the spatial variability of its material characteristics which, in particular, explains the observed or measured reduction of the tensile strength at first crack when the volume under tension increases. This paper discusses the ability of accounting for the spatial variability of the tensile strength of concrete in RC structures using a stochastic finite element (SFE) method based on random field simulations. In this work, the generation of random fields on the concrete tensile strength aims at computing the force corresponding to the first crack occurrence, and the reduced tensile strength of the structure. The method can be applied in particular to large‐sized structures, which show a pronounced size effect, for different types of loading. The method consists of, first, estimating the mean of the random field, using the analytical approach of the weakest link and localization method (WL ). Then, the discretized random field is defined on a particular 2D or 3D grid, and it is finally projected on the finite element mesh of the studied structure. The study of the parameters that influence the prediction of the cumulative density functions (CDFs) of the rupture force or the tensile strength is highlighted using experimental series of concrete beams having different volumes and subjected to 4‐point bending loading. Moreover, the SFE method is applied to a RC tie‐beam under tensile loading, characterized by a weak stress gradient, which complicates the prediction of crack positions.

Investigation of the effect of storage on the structural-mechanical and sensory properties of pear alginate-carragean jelly

The aim of the present study was to investigate the effect of storage on the structural-mechanical and sensory properties of pear alginate-carrageenan jelly during storage at different temperatures. The structural-mechanical and sensory characteristics of the fruit jellies were determined using a texture analyzer and sensory analysis. Sodium alginate and iota-carrageenan were used as gelling agents to prepare the jellies. The main raw material was pure pear juice without added dyes, sugars or preservatives. The storage conditions are 22ᵒC and refrigerated (3ᵒC) temperature for a storage period of up to 60 days. Eight types of structural-mechanical properties (rupture force, rupture deformation, tensile strength, hardness, rupture energy, toughness, Young’s modulus and adhesiveness) were determined and four the type of sensory characteristics (color, aroma, taste and texture) of alginate-carrageenan fruit jellies were evaluated. It was found that storage time and temperature have the greatest and most significant increasing effect on rupture force, compressive force and Young’s modulus and the opposite effect on rupture deformation and adhesiveness after 20 days of storage. The sensory properties of jellies are greatly influenced by both temperature and storage period. Color, aroma and flavor are better accepted by panelists and are preserved to a greater extent during refrigerated storage, while texture is better preserved at room temperature.

Moisture dependent physical, mechanical, and aerodynamic properties of Simarouba glauca seed: A potential tree born oilseed

AbstractThe present study investigates the moisture dependence of the physical, mechanical and aerodynamic properties of Simarouba seeds within the moisture range of 9.24‐22.46% d.b. The length, width and thickness significantly increased from 19.43 to 22.71 mm, 11.52 to 13.88 mm and 9.79 to 11.34 mm respectively. Our findings showed significant effect of moisture content on the one thousand unit mass, bulk density, true density, and porosity which varied in the range of 1050.41g and 1204.7g, 638.88 to 503.88 kg∙m−3, 999.57 to 970.26 kg∙m−3 and 36.08% to 48.06%. Moisture content was found to have positive effect on the angle of repose terminal velocity and static coefficient of friction for all surfaces studied. A decreasing trend in rupture force and increasing trend in deformation with moisture content was also observed. The understanding of these properties as per the present study would be useful for designing post‐harvest processing equipment and storage of Simarouba seeds.Practical applicationsSimarouba glauca, D.C. is an evergreen potential tree born oilseed tree with high scope for biodiesel and edible oil production. The oilseed is presently underutilized due to lack of availability of suitable processing equipment. The findings of the study provide a comprehensive design database related to engineering properties of Simarouba seeds. The predictive models developed in this study can be used to assess the seed properties at any given moisture content range. The enrichment of database would serve as a guide for agricultural engineers, and food processors in the design and development of relevant post‐harvest handling, and processing equipment for Simarouba seeds. This may further lead to promotion of Simarouba processing as a promising enterprise in rural India.

Cell Adhesion, Elasticity, and Rupture Forces Guide Microbial Cell Death on Nanostructured Antimicrobial Titanium Surfaces.

Naturally occurring and synthetic nanostructured surfaces have been widely reported to resist microbial colonization. The majority of these studies have shown that both bacterial and fungal cells are killed upon contact and subsequent surface adhesion to such surfaces. This occurs because the presence of high-aspect-ratio structures can initiate a self-driven mechanical rupture of microbial cells during the surface adsorption process. While this technology has received a large amount of scientific and medical interest, one important question still remains: what factors drive microbial death on the surface? In this work, the interplay between microbial-surface adhesion, cell elasticity, cell membrane rupture forces, and cell lysis at the microbial-nanostructure biointerface during adsorptive processes was assessed using a combination of live confocal laser scanning microscopy, scanning electron microscopy, in situ amplitude atomic force microscopy, and single-cell force spectroscopy. Specifically, the adsorptive behavior and nanomechanical properties of live Gram-negative (Pseudomonas aeruginosa) and Gram-positive (methicillin-resistant Staphylococcus aureus) bacterial cells, as well as the fungal species Candida albicans and Cryptococcus neoformans, were assessed on unmodified and nanostructured titanium surfaces. Unmodified titanium and titanium surfaces with nanostructures were used as model substrates for investigation. For all microbial species, cell elasticity, rupture force, maximum cell-surface adhesion force, the work of adhesion, and the cell-surface tether behavior were compared to the relative cell death observed for each surface examined. For cells with a lower elastic modulus, lower force to rupture through the cell, and higher work of adhesion, the surfaces had a higher antimicrobial activity, supporting the proposed biocidal mode of action for nanostructured surfaces. This study provides direct quantification of the differences observed in the efficacy of nanostructured antimicrobial surface as a function of microbial species indicating that a universal, antimicrobial surface architecture may be hard to achieve.

Azobenzene as a photoswitchable mechanophore.

Azobenzene has been widely explored as a photoresponsive element in materials science. Although some studies have investigated the force-induced isomerization of azobenzene, the effect of force on the rupture of azobenzene has not been explored. Here we show that the light-induced structural change of azobenzene can also alter its rupture forces, making it an ideal light-responsive mechanophore. Using single-molecule force spectroscopy and ultrasonication, we found that cis and trans para-azobenzene isomers possess contrasting mechanical properties. Dynamic force spectroscopy experiments and quantum-chemical calculations in which azobenzene regioisomers were pulled from different directions revealed that the distinct rupture forces of the two isomers are due to the pulling direction rather than the energetic difference between the two isomers. These mechanical features of azobenzene can be used to rationally control the macroscopic fracture behaviours of polymer networks by photoillumination. The use of light-induced conformational changes to alter the mechanical response of mechanophores provides an attractive way to engineer polymer networks of light-regulatable mechanical properties.

Study on Mechanical Properties of Tomatoes for the End-Effector Design of the Harvesting Robot

Agricultural robotics has emerged as a research area within robotics, with a particular focus on designing end effectors that are adapted to the physical characteristics of the target fruits. Acquiring a comprehensive understanding of the physical and mechanical properties specific to tomato fruits not only minimizes mechanical damage during grasping processes but also serves as a foundation for the optimal design of gripping components. In this study, the Syngenta Sibede variety of tomatoes was used as the experimental material. The reversible viscoelastic behavior and deformation characteristics of tomato fruits were approximated using a four-element Burgers model through creep testing. The fitting coefficients for the model exceeded 0.99. The creep parameters for the four ripening stages of tomatoes were obtained, and the correlation between the ripening stage, deformation value, and creep parameters was analyzed. Correlation analysis was performed to examine the relationships between each parameter and creep deformation, revealing significant and highly significant correlations. Inter-parameter correlations were also found to be highly significant. Puncture tests were conducted on tomatoes. The exocarp rupture force of the green-ripening stage was 9.224 ± 0.901 N, which was 53.87%, 70.63%, and 104.01% higher than that of the semi-ripening stage, early firm-ripening stage, and mid-late firm-ripening stage, respectively. This study suggests that when harvesting tomatoes at the semi-ripening stage and beyond, attention should be paid to trimming the stem. Compression experiments were conducted on tomatoes, and it was discovered that under the same ripening stage, the axial compressive rupture force of tomatoes was greater than the radial rupture force. Tomatoes exhibited anisotropic behavior. The grasping direction is axial, which can be used as the new design direction of the end-effector.

Microscopic theory, analysis, and interpretation of conductance histograms in molecular junctions

Molecular electronics break-junction experiments are widely used to investigate fundamental physics and chemistry at the nanoscale. Reproducibility in these experiments relies on measuring conductance on thousands of freshly formed molecular junctions, yielding a broad histogram of conductance events. Experiments typically focus on the most probable conductance, while the information content of the conductance histogram has remained unclear. Here we develop a microscopic theory for the conductance histogram by merging the theory of force-spectroscopy with molecular conductance. The procedure yields analytical equations that accurately fit the conductance histogram of a wide range of molecular junctions and augments the information content that can be extracted from them. Our formulation captures contributions to the conductance dispersion due to conductance changes during the mechanical elongation inherent to the experiments. In turn, the histogram shape is determined by the non-equilibrium stochastic features of junction rupture and formation. The microscopic parameters in the theory capture the junction’s electromechanical properties and can be isolated from separate conductance and rupture force (or junction-lifetime) measurements. The predicted behavior can be used to test the range of validity of the theory, understand the conductance histograms, design molecular junction experiments with enhanced resolution and molecular devices with more reproducible conductance properties.

Preparation and performance assessment of high-strength polyurea microcapsules

Formulation of microcapsules with high mechanical strength holds great significance for their application in high-pressure scenarios. In this study, polyurea (PU) was employed as the shell material to encapsulate perfume oil through interfacial polymerization. Subsequently, a systematic assessment of mechanical strength was conducted. The results indicated that the protective colloid, triethylenediamine (TEDA) concentration, core/shell ratio (perfume oil to polymethylene polyphenyl isocyanate (PAPI)), and reaction temperature, significantly influenced the mechanical strength of PU microcapsules. Notably, employing a concentration of 1.5 wt% polyvinyl alcohol (PVA), 0.5 wt% TEDA, a core/shell ratio of 10:1, and a reaction temperature of 70 °C resulted in PU microcapsules boasting an average rupture force of 1.92 ± 0.22 mN and a Young's modulus of 0.0195 ± 0.0013 GPa. Impressively, when contrasted with melamine-formaldehyde microcapsules, those with PU shells exhibited markedly enhanced mechanical properties.

Mechanical properties of corn: Correlation with endosperm hardness

AbstractThe purpose of this study was to explore the effects of different factors on the compressive mechanical properties of corn kernels. Explore the relationship between endosperm hardness and compressive mechanical properties of corn kernels by polynomial regression analysis. The results showed that the variety and kernel orientation had a significant effect on the compressive mechanical properties of corn kernels. Flint corn had a stronger ability to resist damage than floury corn. As the loading rate increased from 5 to 25 mm/min, the rupture force and rupture energy of corn kernels changed accordingly. The hardness of horny endosperm was significantly higher than that of floury endosperm. The dense starch‐protein network structure of horny endosperm leads to higher hardness. According to the fitting results, the compressive mechanical properties of corn kernels could be predicted using the hardness of the horny endosperm within a certain range.Practical applicationsAs a widely planted food crop in the world, corn is not only an important food crop, but also a high‐quality feed for livestock and poultry. The compressive mechanical properties (elastic modulus, compressive failure force, failure energy, etc.) of corn kernels were explored, and the relationship between endosperm hardness and its mechanical properties was analyzed. It can provide technical parameters for mechanical processing equipment, reduce the loss of corn grain in the processing process, and improve its economic value.

Finite element modeling of tensile behavior for different woven fabrics

Modeling the mechanical behavior of different materials has been always one of the challenging topics and among them, the modeling of textile materials such as fabrics or composites due to their unique structure has attracted the attention of many researchers. In this study, it was tried to model the tensile behavior of woven fabrics with the plain, twill and customized patterns using the finite element modeling (FEM) by considering the yarn progressive damage. The trial and error method was used to find the damage parameters such as the effective plastic displacement for the warp and weft yarns based on the behavior of ductile materials. The obtained error in predicting the rupture force of warp and weft in FEM was less than 8%. After that, the defined yarns were used to model the unit cell of the woven fabrics based on the Pierce’s model. Then, the tensile test of the fabrics in the warp and weft directions was simulated using FEM on the unit cell. Comparing the FEM outputs and corresponding experimental data, it was found that the larger the unit cell dimensions, the less uniform the fabric, so the simulation behavior would be less similar to the experimental one. Finally, the lowest errors of FEM in predicting the fabric rupture force in two directions of the warp and weft were equal to 5% and 15%, respectively, which was related to the plain samples (fully interlaced fabric).