Elastic Modulus Values Research Articles

Modeling of free vibrations and resonant frequencies of simply-supported submerged horizontal plate.

A theoretical approach was applied to study the vibration of simple-supported submerged horizontal plate. The derived analytical solution was used to determine natural frequencies for a horizontal plate vibrating in fluid. The investigations were conducted for a very wide range of material density and elasticity modulus covering all materials used in engineering practice. Analysis shows that plate vibration frequency decreases with increasing plate width and draft, and decreases with decreasing plate thickness. Moreover, the results show that a substantial effect on vibration of submerged plate has mass of water above plate. The results also show that plate vibration frequency decreases with increasing plate material density and decreases with decreasing elasticity modulus. The dominant factors affecting the vibration of the submerged plate are the plate width, the plate thickness, and elasticity modulus. For moderate and low values of elasticity modulus, vibration frequency is becoming lower than frequency of water waves. This is very important because wave frequencies overlap with the natural plate vibration frequencies, which may lead to resonance and failure of a structure. The problem is that the overlap of plate vibration frequencies and wave frequencies occurs for very wide range of wave and plate parameters. Laboratory experiments confirm theoretical results.

Influence of printing orientation on mechanical properties of aged 3D-printed restorative resins

ObjectiveTo evaluate the influence of printing orientation on flexural strength (σf) and elastic modulus (E) of different 3D printing dental restorative resins. MethodsBar-shaped specimens (n = 20) were fabricated from two SLA-printed resins (FT- Formlabs Temporary, and FP- Formlabs Permanent) and two DLP-printed resins (DFT- Detax Freeprint Temp, and GCT- GC Temporary) using two building orientations (0º and 90º). The 3D-printed structures were aged (14 d) before submitted to three-point bending in 37ºC distilled water at a crosshead speed of 1.0 ± 0.3 mm/min until fracture to calculate the σf and the E values. The fractured surfaces were evaluated using stereomicroscopy and scanning electron microscopy (SEM) following fractography principles. Data were statistically analyzed using two-way ANOVA and Tukey post-hoc (α = 0.001). ResultsFP and FT showed significantly higher E values than DFT and GCT, irrespectively of printing orientation (p < 0.001). There was no statistical difference between the building orientations (0º and 90º) for the mean σf and E values for the resin materials evaluated. Fractographic characteristics were similar for the surface fracture from all the materials evaluated, showing typical brittle fracture behavior. SignificancePrinting orientation did not influence of flexural strength and elastic modulus values for the 3D-printed resin structures evaluated. Surface topography was mostly governed by the 3D printer type.

Kuat Lentur Balok Laminasi Kayu Mangga Berbasis Defeleksi dan Regangan dengan Sistem Pembebanan Four Point Bending

To meet the standard needs of low-quality wood structures, special methods are needed that can meet these needs. So the shape of the structure was developed, not whole wood but laminated components made through gluing or commonly called laminated beams This study aims to determine the difference between laminated beams and solid blocks of mango wood through testing the bending strength of beams. The research method used in this study uses quantitative methods with an experimental method approach. The research conducted used Mango wood samples with two types of block treatment, namely laminated beams and solid blocks. The laminated beam is made using 5 layers of Mango wood with a size after lamination of 1200 x 100 x 50 mm. As for solid beams using a size of 1200 x 100 x 50 mm. Then the wood is tested by applying two centralized loads on two pedestals at a distance of 30 cm from the pedestal. The results showed that from testing mechanical properties which in this case is limited only by flexural strength testing. The flexural strength test in question is four point bending. The results of the flexural strength test obtained an average value of modulus of elasticity (MOE) of laminated beams of 6804.796 MPa while for solid beams of 9130.465 MPa. According to SNI 7973-2013. The average value of bending strength (MOE) was obtained 6804.796 MPa for laminated wood and 9130.465 MPa for solid wood. According to SNI 7973-2013, the value of laminated wood in this study is included in the E13 quality code. As for solid wood, it is included in the E18 quality code. This shows that the MOE value of solid beams is greater than the MOE of laminated beams. Then in the modulus of rapture (MOR) test, the average MOR value of laminated beams was 66.205 MPa and solid beams of 95.007 MPa. This shows that the MOR value of laminated beams is smaller than the MOR value of solid beams.

Comparison of the Biomechanical Properties between Healthy and Whole Human and Porcine Stomachs.

Gastric cancer poses a societal and economic burden, prompting an exploration into the development of materials suitable for gastric reconstruction. However, there is a dearth of studies on the mechanical properties of porcine and human stomachs. Therefore, this study was conducted to elucidate their mechanical properties, focusing on interspecies correlations. Stress relaxation and tensile tests assessed the hyperelastic and viscoelastic characteristics of porcine and human stomachs. The thickness, stress-strain curve, elastic modulus, and stress relaxation were assessed. Porcine stomachs were significantly thicker than human stomachs. The stiffness contrast between porcine and human stomachs was evident. Porcine stomachs demonstrated varying elastic modulus values, with the highest in the longitudinal mucosa layer of the corpus and the lowest in the longitudinal intact layer of the fundus. In human stomachs, the elastic modulus of the longitudinal muscular layer of the antrum was the highest, whereas that of the circumferential muscularis layer of the corpus was the lowest. The degree of stress relaxation was higher in human stomachs than in porcine stomachs. This study comprehensively elucidated the differences between porcine and human stomachs attributable to variations across different regions and tissue layers, providing essential biomechanical support for subsequent studies in this field.

Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber

ABSTRACT Oil palm wood is mainly low in density and since strength and stiffness correlate with density, this study aimed to enhance the properties of oil palm wood through thermo-hygro-mechanical (THM) densification. In contrast to other studies using small laboratory-sized specimens, this study examined the densification of oil palm boards in sawn timber dimensions of 2.0 m length. Modulus of elasticity (MOE) and modulus of rupture (MOR) in bending, shear strength and shear modulus parallel by two-plate shear test and Young’s modulus in the three main directions as well as shear modulus in the three planes by ultrasonic testing were determined at densified and undensified specimens. The bending properties were increased to considerably higher levels and a compression ratio of 60% showed higher MOE and MOR values than that of 40%; whereas for boards of the inner part of the trunk, a compression ratio of 60% showed better results than that of 75%. The shear properties were only slightly increased through densification. Densification can improve the properties of oil palm wood. However, the wide range of density and properties found in natural oil palm wood is also present in densified oil palm wood.

High-Performance PEEK/MWCNT Nanocomposites: Combining Enhanced Electrical Conductivity and Nanotube Dispersion.

High-performance engineering thermoplastics offer lightweight and excellent mechanical performance in a wide temperature range. Their composites with carbon nanotubes are expected to enhance mechanical performance, while providing thermal and electrical conductivity. These are interesting attributes that may endow additional functionalities to the nanocomposites. The present work investigates the optimal conditions to prepare polyether ether ketone (PEEK)/multi-walled carbon nanotube (MWCNT) nanocomposites, minimizing the MWCNT agglomerate size while maximizing the nanocomposite electrical conductivity. The aim is to achieve PEEK/MWCNT nanocomposites that are suitable for melt-spinning of electrically conductive multifilament's. Nanocomposites were prepared with compositions ranging from 0.5 to 7 wt.% MWCNT, showing an electrical percolation threshold between 1 and 2 wt.% MWCNT (107-102 S/cm) and a rheological percolation in the same range (1 to 2 wt.% MWCNT), confirming the formation of an MWCNT network in the nanocomposite. Considering the large drop in electrical conductivity typically observed during melt-spinning and the drawing of filaments, the composition PEEK/5 wt.% MWCNT was selected for further investigation. The effect of the melt extrusion parameters, namely screw speed, temperature, and throughput, was studied by evaluating the morphology of MWCNT agglomerates, the nanocomposite rheology, and electrical properties. It was observed that the combination of the higher values of screw speed and temperature profile leads to the smaller number of MWCNT agglomerates with smaller size, albeit at a slightly lower electrical conductivity. Generally, all processing conditions tested yielded nanocomposites with electrical conductivity in the range of 0.50-0.85 S/cm. The nanocomposite processed at higher temperature and screw speed presented the lowest value of elastic modulus, perhaps owing to higher matrix degradation and lower connectivity between the agglomerates. From all the process parameters studied, the screw speed was identified to have the higher impact on nanocomposite properties.

Plant Biomimetic Principles of Multifunctional Soft Composite Development: A Synergistic Approach Enabling Shape Morphing and Mechanical Robustness.

Plant tissues are constructed as composite material systems of stiff cellulose microfibers reinforcing a soft matrix. Thus, they comprise smart and multifunctional structures that can change shape in response to external stimuli due to asymmetrical fiber alignment and possess robust mechanical properties. Herein, we demonstrate the biomimetics of the plant material system using silk fiber-reinforced alginate hydrogel matrix biocomposites. We fabricate single and bilamellar biocomposites with different fiber orientations. The mechanical behavior of the biocomposites is nonlinear, with large deformations, as in plant tissues. In general, the bilamellar system shows increased modulus, strain UTS, and toughness compared to the single-lamellar system for most of the tested orientations. Overall, the biocomposites present a wide range of elastic modulus values (3.0 ± 0.6-104.7 ± 11.3 MPa) and UTS values (0.23 ± 0.04-12.5 ± 2.0 MPa). The bilamellar biocomposites demonstrated shape-transforming abilities with diverse morphing modes, emulating different plant tissues and creating complex shape-morphing structures. These multifunctional biocomposites possess tunable and robust mechanical properties, controllable shape-morphing deformations, and the ability to self-controlled encapsulation, grip, and release objects. By harnessing biomimetic principles, these soft, smart, and multifunctional materials hold potential applications spanning from soft robotics, medicine, and tissue engineering to sensing and drug delivery.

Fatigue behavior investigation of artificial rock under cyclic loading by using discrete element method

In numerous engineering projects, such as tunnel construction, underground gas storage in caverns, and the impact of earthquakes, rock materials experience cyclic loading. However, the response of rock materials to cyclic loading, which may vary in terms of waveform, frequency, and amplitude, is not uniform. Consequently, comprehending the mechanical attributes and fatigue behavior of rocks holds significant importance in engineering designs. This study focuses on subjecting a collection of cylindrical concrete specimens, categorized into three groups with distinct mechanical properties, to both monotonic and cyclic loading within a laboratory environment. Three groups of cylindrical concrete samples with different mixing designs are prepared to evaluate the effect of the mechanical strength of the samples on the fatigue response of the rock. In such a way that: The first group (G1) with Uniaxial Compressive Strength (UCS): 19 MPa, the second group (G2) with (UCS): 49 MPa, and the third group (G3) with (UCS): 71 MPa. In addition, the discrete element method is utilized to simulate uniaxial cyclic compression tests under various loading conditions, such as monotonic and cyclic loading. The resulting fracture propagation patterns and geometries are then analyzed. Numerical and experimental results show that the cyclic uniaxial compressive strength, due to the presence of damage and fatigue phenomena, has decreased relative to the monotonic tests. Also the cyclic elastic modulus values (Ec) have decreased by 53 %, 25 %, and 11 % relative to the monotonic elastic modulus (Em) for the three groups of G1, G2, and G3, respectively. The Stress-life (S-N) model is used to express the fatigue behavior of rock, and the final equation for the S-N model is expressed.

Effect of Thermal Modification on the Density, Durability, Dimensional Stability, and Mechanical Properties of Pinus caribaea

Pinus caribaea (Pine) is an underutilized timber species in Sri Lanka due to its low density, durability, dimensional stability, and undesirable colour. This research aims to examine the enhancements in the physical and mechanical properties of Pinewood through thermal modification (TM) and compare the properties of the TM wood with kiln-dried and untreated wood and with the properties of high-graded timbers of Tectona grandis (teak) and Koompassia malaccensi (kempas). TM is a process that involves heating wood to high temperatures (2000 C) in the absence of oxygen, which removes the moisture and creates changes in the wood at the cellular level. The effectiveness of the thermal modification on density, modulus of rupture (MOR), modulus of elasticity (MOE), moisture content, dimensional stability, durability, and colour was studied. Specific gravity of thermally modified wood was 6% higher than untreated wood, but lower than teak and kempas. MOR and MOE values were 35.75% and 46.46% respectively higher than untreated wood. Equilibrium moisture content was reduced after TM and volumetric shrinkage of TM was reduced to 2.16% and swelling under liquid water contact was reduced to 2.37%. Thermally modified timber was classified as not durable (DC 5) based on field test (EN 252, 2014) results. However, TM timber was slightly durable (DC 4) according to laboratory tests and showed better fungal resistance. The wood underwent a darkening effect as a result of thermal modification, resembling the colour of teak. The cost of TM was 13.1% higher than kiln drying. Improved dimensional stability, enhanced bending strength, and attractive appearance demonstrate the potential of thermal modification as a promising alternative for transforming P. caribaea wood into high-value raw material. TM timber finds suitable applications in indoor furniture and joinery projects. However, due to its lack of termite resistance, preservative treatment is recommended for outdoor ground contact usage.&#x0D; &#x0D; Keywords: Thermally modified timber, Mechanical properties, Dimensional stability, Durability,&#x0D; Pinus caribaea&#x0D;

Uniaxial mechanical stretch properties correlated with three-dimensional microstructure of human dermal skin.

The intact and healthy skin forms a barrier to the outside world and protects the body from mechanical impact. The skin is a complex structure with unique mechano-elastic properties. To better direct the design of biomimetic materials and induce skin regeneration in wounds with optimal outcome, more insight is required in how the mechano-elastic properties emerge from the skin's main constituents, collagen and elastin fibers. Here, we employed two-photon excited autofluorescence and second harmonic generation microscopy to characterize collagen and elastin fibers in 3D in 24 human dermis skin samples. Through uniaxial stretching experiments, we derive uni-directional mechanical properties from resultant stress-strain curves, including the initial Young's modulus, elastic Young's modulus, maximal stress, and maximal and mid-strain values. The stress-strain curves show a large variation, with an average Young's modules in the toe and linear regions of 0.1 MPa and 21 MPa. We performed a comprehensive analysis of the correlation between the key mechanical properties with age and with microstructural parameters, e.g., fiber density, thickness, and orientation. Age was found to correlate negatively with Young's modulus and collagen density. Moreover, real-time monitoring during uniaxial stretching allowed us to observe changes in collagen and elastin alignment. Elastin fibers aligned significantly in both the heel and linear regions, and the collagen bundles engaged and oriented mainly in the linear region. This research advances our understanding of skin biomechanics and yields input for future first principles full modeling of skin tissue.

Study on Rock Mechanics Parameter Prediction Method Based on DTW Similarity and Machine-Learning Algorithms

Rock mechanics parameters are crucial factors for predicting rock behavior in oil and gas reservoirs, optimizing extraction strategies, and ensuring drilling safety. In this study, we propose a random forest (RF)-convolutional neural network (CNN)-long-term short-term memory network (LSTM) fusion model based on the dynamic time warping (DTW) algorithm to construct intelligent prediction models for elastic modulus, Poisson’s ratio, and compressive strength using real-time drilling engineering data. An autoencoder with a sliding window is employed to automatically identify abnormal points or segments in the calculated values of elastic modulus, Poisson’s ratio, and compressive strength obtained from drilled wells. These abnormal values are then corrected using a backpropagation (BP) neural network. Compared to single CNN-LSTM or single RF models, the RF-CNN-LSTM fusion model performs better. It achieves this by effectively combining the strengths of different algorithms in predicting outcomes. The accuracy of the RF-CNN-LSTM fusion model is over 94% when compared to the actual values. Furthermore, the analysis of the relative importance of input parameters reveals that weight on bit (WOB), temperature, displacement, equivalent circulation density (ECD), and mud density are the primary input features for predicting elastic modulus. For predicting Poisson’s ratio, the main input features include WOB, mud density, ECD, temperature, pumping pressure, displacement, and rate of penetration (ROP). Similarly, for predicting compressive strength, the main input features consist of WOB, temperature, displacement, ECD, and mud density. The research findings demonstrate that the rock mechanics parameter prediction models based on the RF-CNN-LSTM algorithm using DTW exhibit high computational accuracy in the B oil field of China. These results are significant for gaining a deeper understanding of the variations in rock mechanics parameters and optimizing drilling decisions.

Comparison of the usage of nut shell, walnut shell, and pistachio shell as a reinforcement particle on the mechanical and wear performance of polypropylene

AbstractIn this study, the usability of nutshell, pistachio, and walnut shell wastes as reinforcement materials in industrial applications and their comparisons with each other was examined. For this purpose, composite samples with a polypropylene (PP) matrix were produced and their mechanical and tribological characterizations were performed. As a result of the tensile tests, both the tensile strength and elastic modulus values of all composite specimens are higher than those of pure PP. On the other hand, the value of elongation at break is lower. The sliding wear resistance increases with increasing reinforcement with walnut and pistachio shell reinforcement, whereas the positive effect becomes negative when the nutshell reinforcement is over 3 wt%. All three types of reinforcement positively affected the scratch resistance. Pistachio shell reinforcement gives the best result. It has been determined that the relative cutting volume value of the samples increases with the reinforcement rate and the wear behavior changes from ductile to brittle. In light of these results, it has been seen that nut, pistachio, and walnut shells could be used as reinforcement materials in industrial applications instead of being waste or fuel.

Preparation and characterization of high density polyethylene with TiO2 modified PEG 6000 filler as a landfill liner material

High-density polyethylene is an engineering polymer that is used in bottom liners of landfills. However, to be used in the environment application, it needs to have good mechanical and thermal qualities. Incorporation of inorganic fillers such as titanium dioxide into a polymer aimed at enhancing several features such as mechanical strength, thermal stability, and resistance to surface wear. In this study, HDPE preparation was carried out by adding TiO2 nanoparticles. TiO2 nanoparticles were synthesized using the precursor TiCL4 and then modified with the addition of PEG 6000. Furthermore, the resulting TiO2 was used as a filler in thermoplastic HDPE. Characterization of high-density polyethylene with TiO2 filler as a landfill liner material shows an increase in mechanical and thermal properties. The HDPE sample containing 8%wt filler had the highest tensile strength, measuring at 84.72 Mpa. In contrast, the use of 6wt% filler resulted in the lowest recorded tensile strength, measuring at 56.24 Mpa. The elastic modulus had its highest increase at 8 wt% TiO2, reaching a value of 729.33 MPa. However, the addition of 6 wt% TiO2 resulted in a notable decrease in elastic modulus, with a value of 522.79 MPa. Additionally, it was observed that the highest elongation at break was achieved with a 4% weight filler, resulting in a value of 49.37%. Similar to the reduction observed in the elastic modulus value, the elongation at break exhibited a substantial decrease of 39.22% upon the addition of 6wt% TiO2. DSC scan curves for both the fabricated nanocomposite systems clearly show that they are affected by the nanofiller and its percentage fraction. There was an increase in Tm1 in the composition of 8wt% TiO2, while an increase in Tm2 occurred in 2wt% TiO2. Therefore, HDPE which is given TiO2 filler has the potential to be used as landfill liner material.

Morphology Distribution in Injection Molded Parts.

A more sustainable use of plastic parts makes it necessary to replace current plastic parts with recyclable components, also allowing the modulation of the part properties through the process. Injection molding is one of the most widely used technologies for obtaining rigid plastic parts, so it is crucial to understand how to tailor properties by adopting the correct processing conditions. One way is to perform annealing steps directly inside the mold: in-mold annealing improves the structural integrity and durability of the material, reduces defects, increases the resistance of parts against certain chemicals, reduces wear and tear, increases ductility, and lowers brittleness. In this work, several in-mold annealing steps were conducted, changing the mold temperature and annealing duration selected on the basis of the half crystallization time of the adopted isotactic polypropylene. The typical molded part morphology, composed of oriented layers at the surface, transition zones, and spherulitic core, is strongly affected by in-mold annealing. In particular, the thickness of the oriented layer, which forms in the early phase of the process, decreases, and the spherulites increase in size. Concerning mechanical behavior, the orientation degree mostly determines the elastic modulus value close to the surface, whereas the conditions under which crystallization occurs determine the modulus in the core.

The effect of Nb on the formation of TiO2 anodic coating oxide on Ti–Nb alloys through MAO treatment

This study aims to promote the growth of a porous oxidized coating of TiO2 due to oxidation of the surface of the Ti–Nb alloy substrates (Nb = 5, 10, and 25 wt%) using the micro-arc oxidation (MAO) technique. Using structural (x-ray diffraction) and microstructural (optical, confocal, and scanning electron microscopy) characterization techniques, it was observed that Nb promotes the formation of the β phase in Ti alloys, reducing Vickers microhardness and elastic modulus values. Regarding the MAO coating, the results showed that the TiO2 coatings are in the form of anatase and rutile, where Nb promotes the formation of the rutile phase, increasing the hardness of the coatings. MAO coatings have high roughness values due to the formation of porous structures characteristic of MAO surfaces. Adhesion results show that MAO coatings have low adhesion with the substrate.

Factors Affecting Properties of Polymer Grouted Sands

The aim of this research was to undertake laboratory testing to investigate the beneficial effects of epoxy resin grouts on the physical and mechanical properties of sands with a wide range of granulometric characteristics. Six sands of different particle size and uniformity coefficients were grouted using epoxy resin solutions with three ratios of epoxy resin to water (3.0, 2.0 and 1.5). A set of unconfined compressive strength tests were conducted on the grouted samples at different curing periods and a set of long-term unconfined compressive creep tests in dry and wet conditions after 180 days of curing were also carried out in order to evaluate the development of the mechanical properties of the sands, as well as the impact of water on them. The findings of the investigation showed that epoxy resin resulted in appreciable strength values in the specimens, especially those of fine sands or well graded sands, grouted with the different epoxy resin grouts. Whilst the higher compressive strength and elastic modulus values at the age of 180 days were obtained for the finer sand, which ranged from 2.6 to 5.6 MPa and 216 to 430 MPa, respectively, the lower compressive strength and elastic modulus values were attained for the coarser sand with low values of the coefficient of uniformity, which varied from 0.68 to 2.2 MPa and 75 to 185 MPa, respectively. Moreover, all grouted sands showed stable long-term creep behaviour, with high values of the creep limit ranging from 67.5 to 80% of compressive strength. The presence of water had a negative marginal effect in the majority of the grouted specimens. In terms of physical properties, the permeability and porosity were estimated. The permeability of fine sands or well graded sands was decreased by two to four orders of magnitude. Using laboratory results and regression analysis, three mathematical equations were developed that relate each of the dependent variables of compressive strength, elastic modulus and coefficient of permeability to particular explanatory variables.

The role of carbon addition on properties of boron carbide- silicon carbide composites

In this research, composites were produced by mixing boron carbide (B4C) and silicon carbide (SiC) with varying amounts of carbon (C) and densifying them via spark plasma sintering at 1950 °C for 5 min. The effects of different C contents on the properties of the composites were observed. Density, elastic modulus, microstructure, Vickers hardness, and fracture toughness were evaluated. It has been observed that the oxygen content of starting powders should be matched with the added C content to obtain high density and desirable mechanical properties. The highest density, elastic modulus, and hardness values were obtained in samples containing 1.5 wt% C. The highest elastic modulus was obtained in the 10 wt% B4C–SiC-1.5 wt% C sample, at 451 GPa. The highest hardness value was 32.85 GPa, corresponding to the sample containing 90 wt% B4C–SiC-1.5 wt% C. The highest fracture toughness value was attained by the sample containing 10 wt% B4C–SiC-2.5 wt% C, at 2.87 MPa m1/2. Lastly, the composite samples showed transgranular fracture behavior.

Role of the mechanical microenvironment on CD-44 expression of breast adenocarcinoma in response to radiotherapy

The biological effects of ionizing radiation are exploited in the clinical practice of radiotherapy to destroy tumour cells while sparing the surrounding normal tissue. While most of the radiotherapy research focused on DNA damage and repair, recently a great attention is going to cells' interactions with the mechanical microenvironment of both malignant and healthy tissues after exposure. In fact, the stiffness of the extracellular matrix can modify cells' motility and spreading through the modulation of transmembrane proteins and surface receptors' expression, such as CD-44. CD-44 receptor has held much interest also in targeted-therapy due to its affinity with hyaluronic acid, which can be used to functionalize biodegradable nanoparticles loaded with chemotherapy drugs for targeted therapy. We evaluated changes in CD-44 expression in two mammary carcinoma cell lines (MCF10A and MDA-MB-231) after exposure to X-ray (2 or 10 Gy). To explore the role of the mechanical microenvironment, we mimicked tissues' stiffness with polyacrylamide's substrates producing two different elastic modulus values (0.5 and 15 kPa). We measured a dose dependent increase in CD-44 relative expression in tumour cells cultured in a stiffer microenvironment. These findings highlight a crucial connection between the mechanical properties of the cell's surroundings and the post-radiotherapy expression of surface receptors.

Effects of Sugarcane Bagasse Fiber Additives on the Mechanical Properties of Lime-Based Composites and their Compatibility with Traditional Lime-Based Mortars

This study explored the incorporation of sugarcane bagasse fibers into lime mortars to potentially enhance the mechanical properties and durability of materials used in heritage structures made of unreinforced masonry. Assessment of the mixes and their compatibility with the traditional lime mortar mix used in conservation projects in the Philippines was also performed. Five (5) mortar specimen types containing different fiber content were prepared, each with twelve (12) samples. Flexural strength, compressive strength, ductility, and modulus of elasticity comprise the mechanical properties investigated while visual properties, chemical and mineralogical composition, pore space, mechanical properties, and hydrophilic behavior comprise the criteria for computing incompatibility degrees (IDs). Being the mix traditionally used in local conservation works, Mortar L0 (plain mortar) served as the control. Results showed that Mortars L4.6 (4.6% fiber content), L7.6 (7.6% fiber content), and L10.7 (10.7% fiber content) generally had lower mechanical properties compared to Mortar L0, except for the 14% increase observed in the compressive strength of Mortar L4.6. Mortar L1.5 (1.5% fiber content) had the best results having significant improvement in overall mechanical strength. It exhibited 6.8% increase in flexural strength, 38% increase in compressive strength, and 69.4% increase in modulus of elasticity values. Mortars L1.5, L4.6, L7.6, and L10.7 were computed to have IDs equal to 3.6, 1.1, 1.8, and 3.3, respectively. These indicate low to medium low incompatibility with Mortar L0. These findings highlight the viability of sugarcane bagasse fibers as reinforcement for lime mortars while maintaining sufficient compatibility with traditional lime mixes.

Influence of sintering temperature on Ti6Al4V-Si3N4-ZrO2 ternary composites prepared by spark plasma sintering

In this study, Ti6Al4V-ZrO2-Si3N4 ternary composites were fabricated using a novel spark plasma sintering technique at different temperatures between 950-1200 °C, the pressure of 50 MPa, sintering rate of 100 °C/min, and a holding time of 10 min to determine the effect of sintering temperature on the consolidated composites. The microstructures of the fabricated composites were examined by the scanning electron microscope (SEM-EDX). The distinct phases and the nano-mechanical properties of the composite were determined by the X-ray diffractometer and nanoindenter. The results show a non-linear response. At elevated temperatures from the composite sample, CT1-950 °C to the composite sample, CT2-1100 °C, the densification, and nanomechanical properties experienced an increase, and when the temperature is elevated to 1200 °C, composite CT3 declines in values. However, the relative density of all fabricated composites was above 95%, which suggests an overall good densification via the spark plasma sintering technique. The ternary composite fabricated at 1100 °C, (CT2) attained maximum values of Vickers hardness, elastic modulus, and nano hardness at 7380 MPa, 177.91 GPa, and 60.06 GPa, respectively, while composite CT3 declines at 1200 °C.