Stress-strain Properties Research Articles

A Database of Stress-Strain Properties Auto-generated from the Scientific Literature using ChemDataExtractor

There has been an ongoing need for information-rich databases in the mechanical-engineering domain to aid in data-driven materials science. To address the lack of suitable property databases, this study employs the latest version of the chemistry-aware natural-language-processing (NLP) toolkit, ChemDataExtractor, to automatically curate a comprehensive materials database of key stress-strain properties. The database contains information about materials and their cognate properties: ultimate tensile strength, yield strength, fracture strength, Young’s modulus, and ductility values. 720,308 data records were extracted from the scientific literature and organized into machine-readable databases formats. The extracted data have an overall precision, recall and F-score of 82.03%, 92.13% and 86.79%, respectively. The resulting database has been made publicly available, aiming to facilitate data-driven research and accelerate advancements within the mechanical-engineering domain.

Enhancing Force Absorption, Stress-Strain and Thermal Properties of Weft-Knitted Inlay Spacer Fabric Structures for Apparel Applications.

The pursuit of materials that offer both wear comfort and protection for functional and protective clothing has led to the exploration of weft-knitted spacer structures. Traditional cushioning materials such as spacer fabrics and laminated foam often suffer from deformation under compression stresses, thus compromising their protective properties. This study investigates the enhancement of the force absorption, stress-strain, and thermal properties of weft-knitted spacer fabrics with inlays. Surface yarns with superior stretchability and thermal properties are used and combined with elastic yarns in various patterns to fabricate nine different inlay samples. The mechanical and thermal properties of these samples are systematically analyzed, including their compression, stretchability, thermal comfort, and surface properties. The results show that the inlay spacer fabric exhibits superior compression properties and thermal conductivity compared to traditional laminated foam and spacer fabrics while maintaining stretchability, thus providing better performance than traditional fabrics for protective clothing and wearable cushioning products. This study further confirms that the type of inlay yarn and inlay structure are crucial factors that significantly influence the thermal, tensile, and compressive properties of the fabric. This research provides valuable insights into the design and development of advanced textile structures to improve wear comfort and protection in close-fitting apparel applications.

Time-varying deterioration of bamboo mechanical properties

Bamboo is a type of fast-growing and renewable natural resource that is an ideal building material. In this study, the longitudinal tensile, longitudinal compressive, flexural, longitudinal shear, transverse tensile, and transverse compressive stress-strain and strength properties of bamboo with a period of 240 days were conducted to study the time-varying deterioration performance of bamboo. The results showed that the mechanical properties of bamboo decreased gradually with the passage of time. The transverse compressive strength deteriorated the most, and the longitudinal tensile strength deteriorated the least. After 240 days of tests, bamboo CCS decreased by 52.5% and UTS decreased by 25.4%. Formulas to predict deterioration of mechanical properties were put forward and validated. It was found that the nodes of bamboo influenced its mechanical properties. The deterioration degree of the test specimens with nodes was slightly higher than that of the test specimens without nodes. These findings provide evidence about the deterioration mechanism of bamboo and are significant for promoting the development of bamboo architecture.

Using natural antioxidant Rhubarb extracts in PVA/chitosan bio-adsorbent films for efficient removal of cationic and anionic dyes from polluted water

In this research, sustainable membrane films were developed for removal of cationic and anionic dyes from wastewater based on polyvinyl alcohol/chitosan (PVA/CS) incorporated with natural antioxidant Rhubarb dye (Rh) extracts. Rh dye was extracted from Rhubarb roots by a green method. Three different quantities of Rh dye extracts (i.e., 2.5, 5, and 10 %) were used to fabricate crosslinked PVA/CS films by solvent-casting approach. The fabricated films subjected to different techniques such as X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM-EDX), dynamic mechanical analysis (DMA), as well as antioxidant activity. In all cases, the incorporation of Rh dye extracts inside the composite improved the crystallinity, biocompatibility, stress–strain properties, besides the DPPH scavenging activity reached 42.50 % for PVA/CS-10 % Rh membrane compared to PVA/CS blank (i.e., ∼ 2.10 %). Dyes adsorption including different cationic and anionic dyes implemented for all selected membranes. The data revealed that the membrane containing 10 % Rh dye was the optimum for removal of malachite green oxide (MG, 93 %) as cationic dye and methyl orange (MO, 95.70 %) as anionic dye. Moreover, the kinetics of the removal process exhibited that this process followed the Langmuir, Freundlich, Temkin, Dubinin-Radushkevich models, and the pseudo-1st order kinetic model, with an R2 of 0.998 and 0.943 for MG and MG, respectively. Whereas, the adsorption process corresponded to the Freundlich isotherm model, with coefficients R2 was of 0.989 and 0.988 for MO and MG, respectively. Other parameters including dye concentration, contacting time, pH media, and kinetic studies were also applied on PVA/CS-10 % Rh membrane.

Fundamental influence of irreversible stress–strain properties in solids on the validity of the ramp loading method

The widely used quasi-isentropic ramp loading technique relies heavily on back-calculation methods that convert the measured free-surface velocity profiles to the stress–density states inside the compressed sample. Existing back-calculation methods are based on one-dimensional isentropic hydrodynamic equations, which assume a well-defined functional relationship P(ρ) between the longitudinal stress and density throughout the entire flow field. However, this kind of idealized stress–density relation does not hold in general, because of the complexities introduced by structural phase transitions and/or elastic–plastic response. How and to what extent these standard back-calculation methods may be affected by such inherent complexities is still an unsettled question. Here, we present a close examination using large-scale molecular dynamics (MD) simulations that include the detailed physics of the irreversibly compressed solid samples. We back-calculate the stress–density relation from the MD-simulated rear surface velocity profiles and compare it directly against the stress–density trajectories measured from the MD simulation itself. Deviations exist in the cases studied here, and these turn out to be related to the irreversibility between compression and release. Rarefaction and compression waves are observed to propagate with different sound velocities in some parts of the flow field, violating the basic assumption of isentropic hydrodynamic models and thus leading to systematic back-calculation errors. In particular, the step-like feature of the P(ρ) curve corresponding to phase transition may be completely missed owing to these errors. This kind of mismatch between inherent properties of matter and the basic assumptions of isentropic hydrodynamics has a fundamental influence on how the ramp loading method can be applied.

Application of Digital Image Correlation to Small Punch Test for Determination of Stress–Strain Properties

The analysis of the small punch test is based on the force on the moving punch and the deflection data acquired at a single point of the specimen bottom. However, the spatial distribution of stress and strain at any given instant is non-uniform and its variations with increase in punch penetration are quite complex. In this work, the digital image correlation (DIC) technique is integrated with small punch test for in-situ full field strain measurement in the bottom surface of the specimen. The DIC results reveal that with the progression of deformation, the peak equivalent plastic strain at the bottom surface shifts from the center of the specimen to a characteristic radial location, where the strain rapidly builds up and concentrates leading to instability and cracking. Combining DIC-based strain results with finite element model-based stress estimation at the characteristic radial location, a methodology for determining the stress–strain curve from small punch test is formulated and the outcomes are compared with tensile test results for four different metallic alloys.

Enhancement of the hygrothermal ageing properties of gelatine films by ethylene glycol diglycidyl ether

Owing to the instability of gelatine in hygrothermal environments, gelatine-based cultural heritage undergo various deterioration processes, such as cracking, peeling, warping, curling and fracture, posing significant threats to its long-term preservation. Building on previous research, this study investigates the stability of polyol glycidyl ether–gelatine composite films under high-humidity and high-temperature conditions using ethylene glycol diglycidyl ether (EGDE) as a model compound. The hygrothermal ageing properties of EGDE–gelatine composite films are evaluated in terms of macrosize, mesoscopic structure, surface properties and mechanical properties. Results indicate that EGDE enhances the dimensional stability and swelling ratios of the composite films, stabilizes the pore structure and distribution and maintains the hydrophilicity and molecular structural stability under hygrothermal ageing conditions. Furthermore, the incorporation of EGDE leads to superior stress–strain properties of the composite films in such challenging environments. This study provides valuable experimental data for the preparation and conservation applications of gelatine-based cultural heritage materials.

Numerical Simulation of Vertical Cyclic Responses of a Bucket in Over-Consolidated Clay

Multi-bucket foundations have become an alternative for large offshore wind turbines, with the expansion of offshore wind energy into deeper waters. The vertical cyclic loading–displacement responses of the individual bucket of the tripod foundation are relevant to the deflection of multi-bucket foundations and crucial for serviceability design. Finite element analyses are used to investigate the responses of a bucket subjected to symmetric vertical cyclic loading in over-consolidated clay. The Undrained Cyclic Accumulation Model (UDCAM) is adopted to characterize the stress–strain properties of clay, the parameters of which are calibrated through monotonic and cyclic direct simple shear tests. The performance of the finite element (FE) model combined with UDCAM in simulating vertical displacement amplitudes is evaluated by comparison with existing centrifuge tests. Moreover, the impact of the bucket’s aspect ratio on vertical displacement amplitude is investigated through a parametric study. A predictive equation is proposed to estimate the vertical displacement amplitudes of bucket foundations with various aspect ratios, based on the cyclic displacement amplitude of a bucket with an aspect ratio of unity.

Static analysis of semi‐underground double‐storey squat silo

AbstractThe semi‐underground double‐storey squat silo (SUDSSS) is a new type of silo with the advantages of preserving grain quality. In this paper, a numerical model of SUDSSS was constructed using solid elements. The proposed numerical model was validated by test results of an experimental underground silo, and the results demonstrated that: (1) Before and after backfilling, the radial and circumferential stress of the underground storey reached their maximum at 2/3 from the bottom and 2/3 from the ground surface, respectively; (2) As the height of grain storage increases, the silo wall stress in the overground storey increases. From the top of the underground storey up to 1/4 height of the overground storey, the stress of silo wall increases. (3) For the underground storey, the maximum stress occurs at 1/3 of the way from the apex of bottom cone.Practical applicationsThe semi‐underground double‐storey squat silo is a new grain storage device proposed by this paper, which consists of two layers. The lower layer is located in the ground and can utilize the shallow ground temperature to realize the green and low‐temperature storage of grain, the upper layer is conducive to the turnover of grain, which can ensure the quality of grain storage. The new silo has the advantages of saving land, energy saving and carbon reduction. Based on the silo, this paper investigates the stress–strain properties of the silo before and after soil backfilling during the construction stage, and obtains the change pattern of the static mechanical properties of the silo. This paper analyses the mechanical properties of semi‐underground double‐storey squat silo under different storage conditions at the grain storage stage, and studies the change patterns of the mechanical properties of the silo body under different storage heights.

Stress–Strain Properties of a Microwave-Irradiated Polymer Composite Based on Rubber PDI-3A

Stress–Strain Properties of a Microwave-Irradiated Polymer Composite Based on Rubber PDI-3A

Three‐dimensional (3D) woven flax fiber/polylactic acid (PLA) composites for high flexural strength

AbstractThree dimensional (3D) textiles are preferable reinforcing materials for composites with lightweight and higher mechanical properties. In this study, a 3D woven flax fiber reinforced PLA composite with better flexural and tensile properties was developed. Four hybrid yarns with varied PLA contents were prepared as warp, weft and z‐yarns to weave the 3D preform and then changed to composites through compression molding technology without additional fillers and matrixes. The composite's flexural and tensile properties were studied and an optimum value of 78.0 and 140.0 MPa respectively were found. Stress strain properties were also discussed which implies the flexural elongation is higher than those of tensile values. The microstructure was analyzed using optical microscope and SEM equipment's showed composites with higher PLA content were more brittle due to the PLA inimitable behavior. The thermal properties of the 3D composites made with different Flax/PLA combinations have closer and comparable values. One way ANOVA statistical analysis was done to show the significancy of PLA /Flax mass ratio, which has a significant effect on composite's properties. This study could bring a novel procedural approach for an advanced 3D woven composites for load bearing applications.Highlights 3D woven flax /PLA composite was developed using Flax/PLA hybrid yarns Tensile and flexural properties were studied Flexural strength increases with PLA, but, slightly lower in its strain PLA/Flax mass ratio has a significant effect on composite's properties The mechanical strengths were improved compared to the related findings

A soil base model of adjacent various story structures

In modern geotechnical engineering, owing to the development of information technology and availability of powerful packages for the calculation of the entire base - foundation - structure system, one of the main research areas is to develop, improve and investigate soil base models to ensure the adequate interaction between the components of the system during the construction and operation of buildings and structures (hereinafter referred to as the “structures”). The paper proposes an improved soil base model in the form of a continuous layer of finite distribution capability to simulate and calculate adjacent multistory structures in the base - foundations - structures system using powerful calculation packages such as SOFiSTiK, ABAQUS, PLAXIS, SCAD, Lira and others. The improved model considers the parameters of the stress-strain properties of the soils of the bases, the geometric profile taking account of the distribution capability of the base and different boundary conditions, but differs from the existing models in that it has a stepped geometric profile at the lower boundary of the model because of different compressible layer depths under each foundation of the structures. The use of this model improves the accuracy of simulating a soil base for large-sized foundations of adjacent structures to obtain reliable results of the stress-strain state of the base - foundations - structures system. An example demonstrates how to simulate and calculate raft foundations of a two-section multistory building in the base - foundations - structures system that interacts with an improved soil base model (linear strains of soils under loads are considered here) with reference to different numbers of stories of the sections. The numerical study results show on a specific calculation example that considering different compressible layers depths in the model under differently loaded foundations results in an increase in moment forces of up to 65% as compared with simulating the whole compressible layer, which may lead to the disruption of large-sized raft foundations.

The Experimental Characterization of Iron Ore Tailings from a Geotechnical Perspective

The mining industry produces large amounts of tailings which are disposed of in deposits, which neglects their potential value and represents important economic, social and environmental risks. Consequently, implementing circular economy principles using these unconventional geomaterials may decrease the wide-ranging impacts of raw material extraction. This paper presents an experimental characterization of iron ore tailings, which are the most abundant type of mining waste. The characterization includes various aspects of behavior that are relevant to different types of use as a building material, including physical and identification properties, compaction behavior and stress–strain properties under undrained monotonic and cyclic triaxial loading. The tailings tested can be described as low-plasticity silty sand materials with an average solids density of 4.7, a maximum dry unit weight close to 3 g/cm3 and a higher angle of friction and liquefaction resistance than common granular materials. The experimental results highlight the particular features of the behavior of iron ore tailings and emphasize the potentially promising combination of high shear resistance and high density that favors particular geotechnical applications. Overall, the conclusions provide the basis for promoting the use of mining wastes in the construction of sustainable geotechnical works and underpin the advanced analysis of tailings storage facilities’ safety founded on an open-minded geotechnical approach.

Retrofitting of heat-damaged fiber-reinforced concrete cylinders using welded wire mesh configurations

Abstract Fire damage poses a significant risk to reinforced concrete structures throughout their lifespan. Fire exposure influences the stress-strain properties and durability of concrete, despite its non-flammability. Therefore, the strengthening approach is an economic option for lengthening their lifespan. This paper aims to conduct an experimental investigation into retrofitting heat-damaged fiber-reinforced concrete cylinders using welded wire mesh (WWM) configurations. Four concrete mixes were investigated. In total, 48 concrete cylinders were tested under axial compression until failure. The primary variables considered in the testing program consisted of (i) the influence of various fiber types (steel fiber (SF), polypropylene (PP), and hybrid fibers (SF+PP)); (ii) exposure temperature (26°C and 600°C); and (iii) WWM strengthening. Exposure to a temperature of 600°C led to a significant reduction in the compressive strength, ranging from 23.7% to 53.3%, while the inclusion of fibers has a substantial effect on the compressive strength of concrete, regardless of fiber type, with an increased ratio reaching up to 34.7%. The finding also clearly shows that the strengthening of heat-damaged specimens with WWM jacketing resulted in a 38.8%, 4.9%, and 9.4% increase in compressive strength for SF, PP, and SF+PPF specimens, respectively, compared to unheated control specimens. The suggested approaches to strengthening, which involve the use of WWM jacketing with two layers, successfully restored and surpassed the initial concrete compressive strength of the specimens that were damaged due to exposure to high temperatures.

A novel in-situ dynamic mechanical analysis for human plantar soft tissue: The device design, definition of characteristics, test protocol, and preliminary results

The in-situ mechanical characterization of elastomers is not highly regarded due to the existence of a well-established set of sample-based standard tests for research and industry. However, there are certain situations or materials, like biological soft tissue, where an in-situ approach is necessary due to the impossibility of sampling from a living body. We have developed a dynamic mechanical analysis (DMA)-like device to approach in-vivo and in-situ multidimensional stress-strain properties of human plantar soft tissues. This work elucidates the operational mechanism of the novel measurement, with the definition of a new set of moduli, test standardization and protocol. Exploratory results of a volunteer's living plantar, silica rubber samples are presented with well preciseness and consistence as expected.

Stress–Strain Properties and Structural Characteristics of a Gamma-Irradiated Polymer Composite Material Based on Low-Molecular-Mass Rubbers

Stress–Strain Properties and Structural Characteristics of a Gamma-Irradiated Polymer Composite Material Based on Low-Molecular-Mass Rubbers

Research on the Compression Performance and Damage Mechanism of Larix Wood With Smooth Grain

In order to investigate the compression performance and damage mechanism of fallen wood in the down-grain direction, northeast larix was taken as the research object. Through the monotonic compression test of 12 specimens, the deformation characteristics, damage mode, and stress-strain curve properties of larix wood under compression in the direction of the smooth grain were analyzed; scanning electron microscope technology was used to analyze the damage and fracture characteristics of wood fibers from the microscopic point of view to further reveal the damage mechanism of wood monotonic compression. The results showed that larix wood compressed in the paragons produced three damage modes of end collapse, shear damage and paragons splitting after the peak load, and the shear damage usually occurred at the junction of the early and late wood tubular cells due to the difference between the early and late wood tubular cells. On this basis, an isomorphic model was established to describe the compression of larix wood in the smooth grain.

A Study on the Reliability Evaluation of a 3D Packaging Storage Module under Temperature Cycling Ultimate Stress Conditions.

Based on the theory of reliability enhancement testing technology, this study used a variety of testing combinations and finite element simulations to analyze the stress-strain properties of 3D packaging storage modules and then evaluated its operating and destruction limits during temperature cycling tests (-65 °C~+150 °C) for the purpose of identifying the weak points and failure mechanisms affecting its reliability. As a result of temperature cycling ultimate stress, 3D packaging storage devices can suffer from thermal fatigue failure in the case of abrupt temperature changes. The cracks caused by the accumulation of plastic and creep strains can be considered the main factors. Crack formation is accelerated by the CTE difference between the epoxy resin and solder joints. Moreover, the finite element simulation results were essentially the same as the testing results, with a deviation occurring within 10%.

Evaluating the tensile properties of high-strength stainless steels using small punch testing.

Accurately measuring the mechanical properties of high-strength stainless steels is of great significance for ensuring structural safety, predicting long-term performance and optimizing design. However, the standardized tensile test specimens used to obtain strength properties must be fabricated from bulk materials from an in-service structure or component, result in the loss of structural integrity or a reduction in remaining service life. Small punch tests require only miniscule material samples and are widely used to estimate in-service component material characteristics. This study performed small punch tests on three high-strength stainless steels-X17CrNi15-2, 15-5PH, and PH13-8Mo-to obtain the correlations between the small punch tests and the uniaxial tensile test results for each material. The estimated yield stresses obtained from the small punch tests were distributed within a factor of 1.5 on both sides of the unity line when compared with those obtained from the uniaxial tensile tests; the ultimate strength values estimated from the small punch tests correlated quite well with those obtained from the uniaxial tensile tests. An iterative finite element analysis was subsequently established to simulate the small punch tests and thereby obtain the coefficients for a Ludwik power law correlation representing the true stress-strain properties. The finite element predicted force-deflection curves agreed well with the small punch test results, which were also compared with the predictions obtained from empirical equations proposed in previous studies. Finally, the fracture mechanisms of the small punch test specimens were characterized through scanning electron microscopy, indicating that the dimple fracture mechanism dominated the failure mode. The results of this study are expected to inform the application of small punch test to evaluate in-service high-strength stainless steel materials.

Properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle Chlorella and its effects on healing of infected full-thickness skin defect wounds in mice

Properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle Chlorella and its effects on healing of infected full-thickness skin defect wounds in mice