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Comprehensive experiments including monotonic tension and monotonic compression of specimens taken from a rolled AZ31B Mg thick plate along five different material orientations with respect to the rolled direction (RD), and free-end torsion of a tubular specimen machined along the thickness direction (ND) were conducted. The experimental results were used to evaluate an elastic-viscoplastic self-consistent model with the consideration of twinning and detwinning (EVPSC-TDT) on magnesium (Mg) alloys. The EVPSC-TDT model provides stress-strain curves and the hardening rates in close agreement with the experimental results of all the 11 loading cases. The model adequately predicts the textures after fracture of all the 11 loading cases and the evolutions of tension twins with increasing strains for tension in the ND, compression in the RD, and torsion along the ND. The Swift effect was observed in the experiment and was properly simulated by the model.

Welded hollow spherical joints are commonly used in reticulated shell structures. Corrosion on the surface of the joints can significantly reduce their compression capacity. Pitting corrosion is a typical corrosion type on steel structures. A corrosion pit forms at random locations and has a random size. Its random size is indicated by random planar size and thickness – that is, multiple-random pitting corrosion. In this work, a series of non-linear numerical analyses was conducted to investigate the influences of these parameters on the mass loss and compression capacity of welded hollow spherical joints. The aim of this work was to construct a probabilistic distribution model of the compression capacity of the joints with multiple-random pitting corrosion and establish the relationship of the probabilistic distribution model with the specified corrosion and geometric parameters. The work also provided a method for determining the probabilistic model of the joints under actual conditions. This work could serve as a basis for the stochastic analysis of integral structures connected by welded hollow spherical joints with random pitting corrosion.

The research examines the outcomes of shear and flexure testing on reinforced concrete beams made from steel and polypropylene fibre. As well as assessing the impact of fibre in this structural integrity with shear strengthening ratios, certain elements in the characteristics of the cement that is both new and hardened are presented. 14 square beams being put into practice. Tests were made. There were beams produced from 7 distinct mixing dimensions, depending on the kind and the fibre content. For each composite mix there were two beams: one with and the other without stirrups. The primary changes caused by the introduction of fibres were enhanced shear strength, rigidity (especially after the first breaking stage) and ductility. The characteristics of hard concrete (tensile strength, compressive strength and elasticity modules), longitudinal reinforcement concrete, stresses in stirrups, were other factors utilized for the analysis of performance (at the compression and web zone).

Twinning-detwinning (TDT) behavior in a strongly basal-textured Mg-Li alloy during two-step compression (RD)-compression (ND) process was investigated using quasi-in-situ EBSD. TDT behavior and TDT variants selection were statistically discussed with the loading path for the first time. Non-Schmid twinning behavior was observed in the first step compression, owing to the local stress fluctuations by neighboring twins; in contrast, Schmid's law well predicted the detwinning variants selection. This asymmetrical TDT behavior was first investigated to date related with the strong basal texture and loading path. Besides, with the progress of compression, Schmid factors for twinning demonstrated a decreasing tendency; however, those for detwinning during the second step displayed an abnormally increasing trend, fundamentally stemming from prior twinning behavior.

The strain characteristic and load transmission of mixed granular matter are different from those of homogeneous granular matter. Cyclic loading renders the mechanical behaviours of mixed granular matter more complex. To investigate the dynamic responses of gravel–sand mixtures, the discrete element method (DEM) was used to simulate the cyclic loading of gravel–sand mixtures with low fines contents. Macroscopically, the evolution of the axial strain and volumetric strain was investigated. Mesoscopically, the coordination number and contact force anisotropy were studied, and the evolution of strong and weak contacts was explored from two dimensions of loading time and local space. The simulation results show that increasing fines content can accelerate the development of the axial strain and volumetric strain but has little effect on the evolution of contact forces. Strong contacts tend to develop along the loading boundary, presenting the spatial difference. Weak contacts are firstly controlled by confining pressure and then controlled by axial stress, while strong contacts are mainly controlled by axial stress throughout the whole cyclic loading. Once compression failure occurs, the release of axial stress causes the reduction of strong contact proportion in all local regions. These findings are helpful to understand the dynamic responses of gravel–sand mixtures, especially in deformation behaviours and the Spatio-temporal evolution of contact forces.

Investigating the damage and ignition behaviors of polymer-bonded explosive (PBX) under a coupled impact and high-temperature loading condition is required for the safe use of charged PBXs. An improved combined microcrack and microvoid model (CMM) was developed for better describing the thermal effects of deformation, damage, and ignition responses of PBXs. The main features of the model under typical dynamic loadings (i.e. uniaxial tension and compression, and lateral confinement) at different initial temperature were first studied. And then the effects of temperature on impact-shear sensitivity of HMX-based PBXs were investigated. The results showed that the ignition threshold velocity of shear-crack hotspots exhibits an increase from 260 to 270 to 315–325 m/s when initial temperature increases from 301 to 348 K; and then the threshold velocity decreases to 290–300 m/s with the initial temperature continually increasing to 378 K. The predicted ignition threshold velocity level of the explosives under coupled impact and high temperature loading conditions were consistent with the experimental data.

YAG (Y3Al5O12) transparent ceramics have attractive application prospects for transparent armor protection modules because of their excellent light transmittance and anti-ballistic capability. Understanding the fracture behavior and damage mechanism of YAG is necessary for armor design. To explore the damage characteristics of YAG under compression and tension, shock compression and shockless spalling experiments with soft recovery technique are conducted. The spall strength of YAG is obtained and the recovered samples are observed by CT and SEM. It is shown that the macroscopic damage characteristic of YAG under compression is vertical split cracks with oblique fine cracks distributed in the entire sample, while that under tension is horizontal transgranular cracks concentrated near the main spall surface. The cracks generated by macroscopic compression, tension and shear stress extend in similar tensile form at the microscale. The proportion of transgranular fractures on spall surfaces is higher than that of cracks induced by macroscopic compression. Meanwhile, higher loading rate and longer loading duration increase the transgranular fracture percentage.

The compression behavior of the lattice-walled tubes under variable strain rates are investigated by numerical simulation, and the stress-strain relationship of the structure under quasi-static loading is theoretically analyzed. The finite element software LS-DYNA is used to simulate the structure established by the beam element, and the critical impact velocity is obtained when the structure collapses layer by layer. According to the plastic hinge theory and considering the combined action of the beam's bending moment and axial force in the structure, the stress-strain relationship of the structure under quasi-static loading is derived and compared with the experimental results. The numerical simulation results reveal that the structure of the single-layer gradient tube(SGC) does not undergo shear deformation under quasi-static and low-speed impact. The critical speed of the gradient square tube(GS) is higher than that of a cylindrical tube. The theoretical model can correctly reflect the mechanical response of the structure under uniaxial compression.

Deep and high-stress mining results in stress transfers onto the previously placed backfill, and mines have recorded several MPa induced backfill stress. Understanding the backfill-rock mass interaction is therefore critical. Previous work considered tabular ore bodies undergoing primarily one-dimensional compression and showed how the backfill reaction curves could be estimated from oedometer laboratory test results. This work considers massive orebodies and develops a similar approach based on isotropic compression curves. Isotropic compression tests exceeding 6 MPa are carried out on samples with 3.0–11.1% binder content, tested at 1-day cure time to 28-day cure time. The compression curve is characterized in three stages: initial elastic compression up to a yield point, followed by a transition stage to the start of a final stage with a linear post-yield compression line in \({\epsilon }_{v}-\text{l}\text{o}\text{g}\left({p}^{\text{'}}\right)\) space. Because these isotropic compression tests are rare (the reported results are the first for Cemented Paste Backfill), attempts are made to relate the isotropic compression test parameters to parameters from the more commonly used Unconfined Compression Strength (UCS) tests. Unifying equations as functions of binder content and cure time are found to determine the initial yield stress and the peak strength from UCS tests. These are then related to the corresponding parameters in isotropic compression. Finally, the slope of the post-yield compression line is found as a function of UCS, thereby enabling complete reconstruction of the isotropic compression response based on parameters from carefully controlled UCS tests, as functions of binder content and cure time. Although the calibrated parameters are specific to the studied mine’s materials, the framework is general and applicable to other mines’ CPBs.

The texture profile analysis test is an imitative test to determine texture properties of food, which quantify the consumer’s perception of eating food. The instrumental texture parameters obtained from this test depend on the specimen size and the nonstandardized test conditions. To overcome this problem, texture properties are here related to intrinsic mechanical properties, which are independent of the test conditions. Two types of materials are used to investigate the effect of viscoelasticity, plasticity and damage on the texture parameters for varying test conditions. Analytical relations between mechanical properties, test conditions, and the instrumental hardness, springiness, cohesiveness, and adhesiveness are determined. The hardness is obtained from the stiffness of the material, which is potentially rate-dependent, and the yield stress of a material in case of plasticity. The springiness is determined by the recoverable or irrecoverable strain in the material, which results from the mechanical properties in combination with the test conditions. Cohesiveness and springiness are found to be strongly related, unless structural damage is present in the material. Adhesiveness is only an indirect measure of the adhesion between the material and compression plate and depends on the test conditions and stiffness of the material. Finite element simulations reveal a decrease of hardness in case of a nonflat top surface, indicating the importance of geometrical effects.

The release and dissolution of an active pharmaceutical ingredient (API) from the solid oral formulation into the gastrointestinal (GI) tract is critical for the drug's absorption into systemic circulation. Extended-release (ER) solid oral dosage forms are normally subjected to physical shear and grinding forces as well as pressure exerted by peristaltic movements when passing through the GI tract. The complex physical contraction and sample friction exerted by the GI tract are not simulated well by compendial dissolution methods. These limitations render traditional in vitro dissolution testing unable to discriminate and predict a product's in vivo performance. The objective of this study was to develop a dissolution method that better simulates the GI environment that products are subject to when taken by patients. A newly designed Mechanical Apparatus under GI Conditions (MAGIC) was assembled with a dissolution platform and mechanical capabilities to allow in vitro dissolution testing under sample contractions and friction. The dissolution platform, with medium flow-through configuration, was manufactured by 3D printing. A 60 mg polymer matrix-based ER nifedipine product was tested. To simulate GI physiological conditions during the dissolution testing, the flow rate of the medium, and a combination of mechanical compression with rotation induced sample friction at various rotation frequencies were explored. The polymer matrix-based nifedipine ER formulation used here failed its controlled release functionality in the simulated GI environment under mechanical compression and sample friction. The results showed that the MAGIC system, with flow-through configuration under compression and sample friction, has advantages over compendial methods in testing ER solid oral formulations.

To study the hot deformation behavior of Mg–8.3Gd–4.4Y–1.5Zn–0.8Mn (wt%) alloy, hot compression tests were conducted using a Gleeble–3500 thermal simulator at temperatures ranging from 653 to 773 K, true strain rates of 0.001–1 s−1, and a deformation degree of 60%. Results of hot compression experiments show that the flow stress of the alloy increases with the strain rate. The true stress–true strain curves are corrected by correcting the effect of temperature rise in the deformation process. Activation energy, Q, equal to 287380 J/mol and material constant, n, equal to 4.59 were calculated by fitting the true stress–true strain curves. Then, the constitutive equation was established and verified via finite element simulation. Results of the hot processing map show that the probability of material instability increases with the degree of deformation, which indicates that the material is not suitable for large deformation in a single pass. On the whole, the alloy is appropriate for multipass processing with small deformation and a suitable processing temperature and strain rate are 733 K and 0.01 s−1, respectively.

The effect of contact pressure on the performance of electrolyte supported planar solid oxide fuel cells (SOFCs) are experimentally investigated in this study by varying the pressure applied on the push rod. For this purpose, cells with 1 cm2, 9 cm2, 16 cm2, 81 cm2 and 150 cm2 active areas are manufactured and tested under different external compression pressures. Maximum power densities of 0.486 W/cm2, 0.308 W/cm2 and 0.231 W/cm2 are obtained from the cells with an active area of 1 cm2, 9 cm2 and 16 cm2, respectively, under the same contact pressure. When the impedance results are considered, it is seen that under the same compression pressure, the cell resistance increases nonlinearly with the cell size. However, when the pressure is adjusted according to the active area, a similar power density of approximately 0.4 W/cm2 is obtained from these three cells. Moreover, very similar performances are measured from all cells when a portion of cells with 1 cm2 active is cut and tested under the same contact pressure of 0.2 MPa. The overall results indicate that the external load should be adjusted according to the cell size, but there is no linear relationship between the active area and the applied external pressure.

The twinning behavior, dynamic recrystallization (DRX) mechanism and the resultant texture evolution of the extruded Mg-xBi (x=0.5 wt.%, 2.0 wt.%) alloys were systematically investigated during hot compression at the strain rate of 10 s−1 and temperature of 200°C. The results indicate that the types and intensities of the texture are greatly dependent on the twining behavior and DRX mechanism. At the initial stage, the evolution of texture is mainly domination by the formation and variation of { 10 1 ¯ 2 } extension twins, which is beneficial to the compression direction (CD) -tilted basal texture. With an increase in the strain, the texture evolution is more greatly regulated by the DRX mechanism. Besides, the pyramidal slip and basal slip are activated during the compression process, resulting in the Schmid factors (SF) of pyramidal slip remain at ∼0.4 and the average SFs for basal slip increase from 0.2 to 0.34 as the strain increase. These findings provide a new insight into controlling the texture of wrought Mg-Bi-based alloys during hot deformation processing.

For estimating the long-term stability of underground framework, it is vital to learn the mechanical and rheological characteristics of rock in multiple water saturation conditions. However, the majority of previous studies explored the rheological properties of rock in air-dried and water saturated conditions, as well as the water effects on compressive and tensile strengths. In this study, andesite was subjected to direct shear tests under five water saturation conditions, which were controlled by varying the wetting and drying time. The tests were conducted at alternating displacement rates under three vertical stresses. The results reveal that the shear strength decreases exponentially as water saturation increases, and that the increase in shear strength with a tenfold increase in displacement rate is nearly constant for each of the vertical stresses. Based on the findings of the shear tests in this study and the compression and tension tests in previous studies, the influences of both water saturation and loading rate on the Hoek-Brown failure criterion for the andesite was examined. These results indicate that the brittleness index of the andesite, which is defined as the ratio of uniaxial compressive strength to tensile strength, is independent of both water saturation and loading rate and that the influences of the water saturation dependence and the loading rate dependence of the failure criterion can be converted between each other.

The use of fibre-reinforced polymers (FRPs) as internal confining reinforcement in combination with longitudinal steel bars in concrete compression members provides significantly improved strength, ductility and durability. To date, only a few experimental studies have been carried out to establish the compressive behaviour of concrete columns longitudinally reinforced with steel bars and confined with FRP ties. This paper provides a confinement model with several expressions for predicting the axial stress–strain response of hybrid-reinforced (i.e. longitudinal steel bars combined with FRP ties) square concrete columns under axial compression loading. The model considers the influences of several test parameters, such as the configuration, size, volumetric ratio, spacing and type of ties (FRP pultruded bar ties and closed-type wound rectangular-section ties). The proposed model predicted well the peak and ultimate strength and strains compared with existing models. The overall accuracy of the model was also assessed against selected test stress–strain responses.

The increase in solid fraction (SF) of a packed granule bed with pressure applied during the in-die compression process results in an evolution of the tablet's matrix and mechanical strength. In this case study, the tensile strength (TS) of a dry granulated microcrystalline cellulose (MCC)/mannitol (MNT)-based formulation was modeled in light of the deformation potential, ∆ (tablet SF – initial granule bed SF). Results showed that the TS of tablets linearly decreased as SF of granules (produced as mini-tablets of an ibuprofen formulation) increased. The formulated granules achieved a measurable tablet strength at a slightly lower critical deformation potential (∆c) than the pure MCC granules. Beyond ∆c, tablet TS increased almost linearly as the deformation potential increased, and the rate was higher for tablets with higher SF. Compared to the simple MCC system, the granules of the MCC/MNT-based formulation were weaker, and TS of tablets increased with deformation potential at a lower rate.

This study investigated the effect of fibre reinforcement on the large strain behaviour of compacted clay samples tested using large triaxial test equipment. A novel specimen preparation method was proposed where peds of clay are compacted to closely simulate the in-situ compaction. A large number of 100 × 200 mm triaxial tests and one-dimensional compression tests were performed using reinforced and unreinforced samples. The behaviour of unreinforced samples was observed to be similar to highly fissured clays; ped compaction generated a random fissure pattern due to the contact between peds. The addition of fibres to the compacted samples created fissures with higher mobility at lower friction than those in the unreinforced samples; hence, the state boundary surface of reinforced clay was below that of the unreinforced clay. With the addition of fibres, the failure mechanism changed from the formation of a shear plane to barrelling, demonstrating that the fibres transferred stresses further away from the shear plane, producing a more homogeneous stress distribution. The preparation method proposed here produced a fissure pattern in the clay that introduced transitional behaviour, which was drastically reduced with addition of the fibres, allowing better normalisation and the definition of a unique boundary surface.

A novel yield criterion based on CPB06 considering anisotropic and tension-compression asymmetric behaviors of magnesium alloys was derived and proposed (called M_CPB06). This yield criterion can simultaneously predict the yield stresses and the Lankford ratios at different angles (if any) under uniaxial tension, compression, equal-biaxial and equal-compression conditions. Then, in order to further describe the anisotropic strain-hardening characteristics of magnesium alloy, the proposed M_CPB06 criterion was further evolved to the M_CPB06ev model by expressing the parameters of the M_CPB06 model as functions of the plastic strain. As the model was developed, the stresses and Lankford ratios of AZ31B and ZK61M magnesium alloys at different angles under tensile, compressive and through-thickness compressive conditions were used to calibrate the M_CPB06/M_CPB06ev and the existing CPB06ex2 model. Calibration results reveal that compared with the CPB06ex2 yield criterion with equal quantity of coefficients, the M_CPB06 criterion exhibits certain advancement, and meanwhile the M_CPB06ev model can relatively accurately predict the change of the yield locus with increase of the plastic strain. Finally, the M_CPB06ev model was developed through UMAT in LS-DYNA. Finite element simulations using the subroutine were conducted on the specimens of different angles to the rolling direction under tension and compression. Simulation results were highly consistent with the experimental results, demonstrating a good reliability and accuracy of the developed subroutine.

Flexible polyurethane foam (FPUF) is the most used polyurethane, but the highly flammable characteristic limits its widespread usage. In this work, ZIF-8@Ti3C2Txwas synthesized to reduce the heat and toxic gases of FPUF. Flame-retardant FPUF was characterized by cone calorimeter (Cone), thermogravimetric analysis/fourier-transform infrared spectroscopy (TG-FTIR), tensileand compression tests. Compared with pure FPUF, these results showed that the peak of heat release rate (PHRR), total heat release (THR), CO and HCN of FPUF6 decreased by 46%, 69%, 27% and 43.5%, respectively. Moreover, the tensile and compression strength of FPUF6 demonstrated a 52% and 130% increment, respectively. The superior dual metal catalytical charring-forming effect and physical barrier effect of ZIF-8@Ti3C2Tx were achieved. In summary, a simple and reliable strategy for preparing flame-retardant FPUF with reinforced mechanical and fire safety properties was provided.

In this study the effects of thermal shock on the impact damage resistance, damage tolerance and flexural strength of Nextel 610/alumina silicate ceramic matrix composites were experimentally evaluated. Composite laminates with balanced and symmetric layup were gradually heated to 1200°C in an air-based furnace and held for at least 30 min before being removed and immersed in water at room temperature. The laminates were then subjected to low velocity impacts via a hemispherical steel impactor. The resultant damage was characterized non-destructively, following which the laminates were subjected to compression tests. Three-point bend tests were also performed to evaluate the effect of thermal shock on the flexural strength and related failure modes of the laminates. Thermally shocked laminates showed smaller internal damage and larger external damage areas in comparison to their pristine counterparts. For the impact energy and resultant damage size considered, the residual compressive strengths for the thermally shocked and pristine laminates were similar.

In this paper we study numerically and experimentally non-reversible deformation of anisotropic, semi-flexible fibre networks. We formulate a Discrete Element Model (DEM) with bonded particles to simulate uniaxial compression of such networks and use this model to describe and quantify the effect of elasto-plastic fibre contacts and fibre-fibre adhesion on non-reversible deformation. Our results show that inter-fibre adhesion plays a role for compression in a low solid volume fraction range where adhesive forces can overcome fibre deformation forces and moments. Also, elasto-plastic contacts between fibres become important at higher solid volume fractions when the yield criterion is exceeded. The combined case of fibres having elasto-plastic contacts and adhesion shows a significant synergetic effect leading to a degree of non-reversible deformation of the network far beyond that of networks with only elasto-plastic fibre contacts or inter-fibre adhesion.

The internal inhomogeneous deformation and re-breaking characteristics of broken rock and coal during compaction are the basis for understanding porous structure evolution of the caved zone and then affect the enrichment of coalbed methane (CBM) in mining gob. In this paper, compression-AE experiments on limestone are carried out using a self-developed AE testing system. An AE location method, which is especially suitable for broken porous media is proposed. The results show that 1) the compression process of broken limestone can be divided into three stages: initial compression, linear compression, and plastic compression. There is a good correspondence between AE counts, energy and compression stages. 2) Broken limestone has layered re-breaking characteristics: the particle re-breaking firstly occurs in the middle layer and gradually moves toward the upper and lower layers as compression degree increases. The ultimate re-breaking degree in upper and middle layers is larger than that in lower layer. 3) The final screened results when strain rate reaches 0.24 show that the reduction of porosity is larger in upper and middle layers than that in lower layer under loading. The lower layer owns the largest porosity due to relative smaller compression degree.

When compared to green sand moulds, resin bound sand moulds and cores have higher mechanical characteristics and create more dimensionally exact castings, and are thus increasingly preferred for near net form metal components. The effect of catalyst %, sand particle size and no. of strokes for compression on collapsibility and core shrinkage of no-bake resin bonded mould core was studied in this study using lab testing. Their collapsibility were discovered to decrease and core shrinkage increase with the addition of catalyst amount and bigger grain size. Microscopic study of cross-linked resin bridges between sand grains also supports this. To get the best blend of mould characteristics, the results were optimized using the Taguchi technique and Sunflower optimization algorithm. Tests were used to successfully validate the model and its findings. It was reported that the Sunflower optimization algorithm made more precise prediction than Taguchi method in maximization of collapsibility and minimization of core shrinkage. This study lays the groundwork for optimizing the moulding parameters of resin reinforced sand mould cores in order to achieve the best quality.

This experimental study emphasizes on the effect of ultrasonication, degassing and stirring process of purenanotubular Halloysite (HNT) on epoxy based composite. This process includes hydraulic compression and moderate pressurized hold under a pressure of 1.1 MPa for the expansion restriction of the composite during solidification. Synthesized composite were evaluated accordance to the processing effect on the microstructure and its interfaces. A compact discussion on the microstructure of the each composite and generated interface has been illustrated. A consolidated effect of processing parameters as ultrasonication, degassing and stirring is observed on the microstructure and XRD results of the synthesized composite. Microstructure results reveal that dispersion of HNT enhanced linearly with an addition of HNT particulates.

Composite materials are developed with the sole intention of augmenting the properties of metal/alloy through the addition of reinforcing materials. The composite of Al-6082 alloy with 5%, 10%, 15% and 20% percent by weight nano-SiC particulate reinforcement was successfully fabricated using the standard stir casting method. Using the rule of mixture, the physical properties such as the density, Poisson’s ratio, and the Young’s modulus were computed for the fabricated composites. The rule of mixture showed that the density and Young’s modulus was highest for composite with 20% nano-SiC reinforcement at 2.802 gms/cm3 and 136.2 MPa respectively. Whereas the Poisson’s ratio was maximum for composite with 5% nano-SiC reinforcement at 0.3225. For the strength evaluation, aappropriate specimens were prepared according to ASTM standards from the fabricated composites to test the hardness, tensile strength, compression strength, and impact strength. The hardness was tested using the Brinell’s hardness tester, which showed an increasing trend in the BHN, from 5% to 20%, at 84.34 to 93.39 N/mm2 respectively. The tensile tests showed an increasing tensile strength with a maximum measured at 327.94 MPa, for composite with 15% SiC. The tensile strength however reduced with further increase in nano-SiC reinforcement content at 20%. The compression tests showed a gradual increase in the compressive strength starting at 28.96 MPa for 5% nano-SiC reinforcement content, to 48.97 MPa for 20% nano-SiC reinforcement content. The impact tests conducted using the Charpy Test showed a gradual decrease in the impact strength starting at 6.2 Joules for 5% nano-SiC reinforcement content, to 4.8 Joules for 20% nano-SiC reinforcement content. This is due to the reducing toughness in the composites with a gradual increase in the nano-SiC reinforcement. The strength evaluation showed that for applications requiring maximum hardness and compression loads, the MMC of Al-6082 with 20% nano-SiC reinforcement would be best suited. It was also concluded that the applications with maximum tensile loading requirements, the MMC of Al-6082 with 15% nano-SiC reinforcement would be suitable. Furthermore, the impact strength evaluations has shown that the composite is highly unsuitable for applications with impact loading conditions.

Lower back pain is one of the most common problems amongst people in this fast-paced life, often caused by degenerative disc diseases in the lumbar region of the spine. Many conventional techniques are commercially available in order to manufacture spinal cages; however, three-dimensional (3D) printing provides the flexibility of creating patient-specific spinal cages depending on the patient’s condition. Indeed, solid cages provide the strength but lack in reducing stress-shielding; hence, creating a porous structure inside the spinal cages can help in reducing the stress shielding effect. In the present work, two cages (solid and Gyroid structure porous plif) have been made of titanium ELI grade by using direct metal laser sintering (DMLS) technique. Compression and fatigue test has been performed in the simulated environment with the help of finite element analysis (FEA) and, thereafter, compared with the physical results. It has been found that Gyroid structured porous cage developed more concentration of the stress when compared to the solid cage; however, it efficiently reduced the stress shielding effect and will promote the bone in-growth.

For metal-intermetallic laminated composites, various types of defects often occur during the preparation process. This paper studied the evolution and formation mechanism of defects, such as pores, tunnel cracks, and delamination cracks in Ti-Al3Ti laminated composites prepared by vacuum hot-pressing method. Moreover, quasi-static and dynamic compression tests were performed to study the effects of pores and delamination cracks on the compression properties of the composites. The results showed that for Ti-Al3Ti laminated composites prepared at 710 ℃, their Al3Ti layers exhibit a porous structure, and the porosity of Al3Ti layers firstly decreases and then increases under the combined action of press, the self-propagating reaction and Al3Ti grain coarsening. The tunnel cracks in Ti-Al3Ti laminated composites are resulted by tensile residual stresses and the inherent brittleness of Al3Ti. For Ti-Al3Ti laminated composites prepared at 680 °C, the formation of delamination cracks is mainly related to the diffuse reaction of Ti/Al atoms and the Kirkendall effect, and the numbers of delamination cracks increase with the increasing of sintering time. Moreover, the pores and delamination cracks greatly deteriorate the compression properties of Ti-Al3Ti laminated composites. Crack-free and dense Ti-Al3Ti laminated composites exhibit the highest compression properties.

Concrete is the ones with compression strongness and weakness in tension. In such a case, reinforcement to the concrete is needed. Primarily steel is utilized as reinforced material. In recent times many industrials and researchers are in the process of finding an alternative material for steel. So studies and research are conducted in the field of artificial fiber. But in this research, more focus is given on natural fiber because these fibers are naturally available. The used fiber for reinforcement is known as the SISAL Fiber [SF], considered the alternative material in mount. The chemical, physical, and structural properties of the fibers are studied in detail. Analyzing the SF showed that the reinforced composite of the sisal fiber is well-grounded in civil and rural construction structural elements. This can be utilized as an alternative to steel since steel materials are hazardous to humans as well as animals. The SF production is compared with synthetic fibers and with mineral asbestos. This sisal fiber is considered the one which is economical in production with social and economic benefit.

This study experimentally explores the effects of applying various types of fibres to concrete mixes on the flexural behaviour of longitudinal structural members with basalt fibre reinforced polymer (BFRP) bars. The main objective is to research the viability of using new advanced fibres of basalt to enhance the concrete response. Basalt fibre and basalt fibre reinforced polymer rebar and compared with the conventional concrete and with a 40 MPa compressive strength target, eighteen beams were fabricated and tested; twelve with basalt fibre reinforced polymer rebar concrete and six with conventional concrete Basalt fibre lengths 30 mm with 15 µm and BFRP bar length of 800 mm with 8 mm diameter were taken into account. Flexural tests were done using a four-point test setup on both of the BFRP- conventional concrete (CC) beams. The test matrix would include BFRP bar reinforcing beams and conventional steel rebar for comparative purposes. Results showed that the application of basalt fibres to concrete enhanced the ductility of these beams' curvature. Due to the delay in the concrete failure in the compression zone, a significant improvement in bending ability was also reported, which supported the BFRP bars achieved a higher ultimate strength. The opening and deep formation of a crack have been effectively limited by the aggregate interlock of basalt fibres, which maintained the crack widths lower than in the 0.7 mm permissible maximum in service. Basalt fibres of 4%, 6%, and 8% were done. Compared to conventional concrete 6% basalt fibre at 28 days of the curing period, the maximum compressive strength was attained 52.38 N/mm2, tensile strength was attained 5.55 N/mm2, Flexural strength increases to 7.45 N/mm2. However, basalt fibre reinforced polymer rebar concrete was larger than conventional concrete beams.

This work on the designing and analysis of micro lattice structures in various configurations. Initially, four different Body-Centered Cubic (BCC) lattice cell structures (LCS) of different strut diameters were designed using SolidWorks. ANSYS Workbench has been used to determine the lattice structure's compression stress analysis and the evaluation of deformation and stress analysis. To estimate the equivalent solid properties: First, the FEA method and theoretical calculations are used on a single unit cell BCC for different cases (different strut diameters and cell sizes). In addition, 10 × 10 × 10 mm (H × L × W) cells with strut diameter 2 mm BCC lattice cell structure specimens are designed and analyzed under compression loading conditions. Within the elastic limit, load–displacement behavior and the results obtained from the FEA models are appreciable. Even though AlSi10Mg materials have good mechanical properties, lattice structures can be used to enhance mechanical and functional properties and parts can be created with regulated porosity.

The simulation-based artificial neural networks (ANN) program is one of the suitable candidates from artificial intelligence simulation which can work to predict important ultrasonic and mechanical parameters in the glass field. This research is focused on exploring the validity of this system by comparing the prediction values from ANN with the experimental measurements and other theoretical models. The ANN simulation was effectively applied to a binary zinc-borate glass system with the composition of zZnO−(100-z)B2O3 where z = 0, 40, 45, 50, 55, and 60 mol%, which was fabricated by using the melt-quenching techniques. The increase of ZnO content caused the ultrasonic velocity and elastic moduli of the glasses to exhibit a decreasing trend. The bond compression theoretical calculation compared with the experimental measurement was considered to be satisfactory with the value of the coefficient R2 being around 0.92452 to 0.98492. The Makishima-Mackenzie calculation model concerning the experimental measurement of the elastic moduli and Poisson's ratio were between 0.86628 to 0.99786. The coefficient R2 value from the ANN simulation displayed on the density, ultrasonic velocity, and elastic moduli graph is around 0.9999 to 1.0000, which is considered to be very reasonable. The values predicted by this remarkable model proved that ANN simulation is suitable for use in glass research.

The responses of Al/PTFE reactive materials (RMs) under shock compression were investigated by a single-stage gas gun. A 3D mesoscale-model was established based on micro-computed tomography (micro-CT) slice images and confirmed with experimental results. In the high-pressure stage, the composites reacted partially, whereas there were no deviations between the partially reacted Hugoniot and the inert simulation results. The simulation reveals that the Teflon matrix melting on the high shock pressure. Melts and decomposition of the PTFE accelerated the diffusion of the atoms. Thus, the reactions of the Al/PTFE composites are more like a combustion rather than a detonation.

Resin uptake plays a critical role in the stiffness‐to‐weight ratio of wind turbine blades in which sandwich composites are used extensively. This work examines the flexural properties of nominally half‐inch thick sandwich composites made with polyvinyl chloride (PVC) foam cores (H60 and H80; PSC and GPC) at several resin uptakes. We found that the specific flexural strength and modulus for the H80 GPC sandwich composites increase from 82.04 to 90.70 kN · m/kg and 6.03 to 7.13 MN · m/kg, respectively, with 11.0% resin uptake reduction, which stands out among the four core sandwich composites. Considering reaching a high stiffness‐to‐weight ratio while preventing resin starvation, 32% to 38% and 40% to 45% resin uptakes are adequate ranges for the H80 PSC and GPC sandwich composites, respectively. The H60 GPC sandwich composites have lower debonding toughness than H60 PSC due to stress concentration in the smooth side skin‐core interphase region. The ailure mode of the sandwich composites depends on the core stiffness and surface texture. The H60 GPC sandwich composites exhibit core shearing and bottom skin‐core debonding failure, while the H80 GPC and PSC sandwich composites show top skin cracking and core crushing failure. The findings indicate that an appropriate range of resin uptake exists for each type of core sandwich composite, and that within the range, a low‐resin uptake leads to lighter blades and thus lower cyclic gravitational loads, beneficial for long blades.

Metal-organic framework (MOF) glasses provide new perspectives on many material properties due to their unique chemical and structural nature. Their mechanical properties are of particular interest because glasses are inherently brittle, which limits their applications as structural materials. Here we perform strain-rate-dependent uniaxial micropillar compression experiments on agZIF-62, agZIF-UC-5, and agTIF-4, a series of MOF glasses with different substituting linker molecules, and find that these glasses show substantial plasticity, at least on the micrometer scale. At a quasi-static strain rate of 0.001 s-1, the micropillars yielded at approximately 0.32 GPa and subsequently deformed plastically up to 35% strain, irrespective of the type of substituting linker. With increasing strain rate, the yield strength of agZIF-62 evolved with the strain-rate sensitivity m = 0.024 to reach a yield strength of 0.44 GPa at a strain rate of 510 s-1. On the basis of this relatively low strain-rate sensitivity and the absence of serrated flow, we conclude that structural densification is the predominant mechanism that accommodates such extensive plasticity.

In this research, an experimental and numerical investigation on the influence of strengthening steel square hollow sections (SHS) subjected to pure torsion with Carbon Fiber Reinforced Polymers (CFRP) wraps. CFRP was widely used to strengthen steel members in bending and compression. Experimental tests were conducted on 8 light-gauged steel SHS having two different cross-sections, SHS 48 × 2 mm, SHS 80 × 2 mm. Four strengthening configurations were tested; namely, Spiral, Reverse, Spiral-Reverse, and Reverse-Spiral. All specimens were wrapped with an orientation angle 45° with respect to the longitudinal axes of the specimen. Results showed that Spiral-Reverse and Reverse-Spiral configurations offered higher capacity enhancement. Strengthened specimens with these configurations reached up to 96% increase in their torsional capacity with respect to the control bare specimen. Spiral and Reverse configurations showed lower torsional capacity enhancement with a maximum percentage of 47%. Finite element models were constructed to simulate the tested specimens. The general purpose finite element program ANSYS was used to establish a numerical model for strengthened SHS incorporating geometric and material non-linearity. The numerical solution was essentially non-linear static analysis at which the load was applied incrementally using the arc-length method. The limit load of strengthened SHS was defined by the load at which the total strain energy reached 1.2 times that of respective bare SHS as per experimental results obtained herein. The proposed numerical model provided compatible results with test results obtained herein and previous literature.

Grain breakage is mainly caused by impact and compression load in harvest and processing. At present, the mechanism of grain breakage under loading, especially the statistics of breakage characteristics, is not clear. The analysis of breakage process of single particle provides a foundation for the understanding of breakage mechanisms. This paper aims to examine breakage behaviour of a single rice particle under compression and impact experiments. Firstly, the equivalent diameter (Dp) and moisture content (MC) of rice particles were regarded as important factors that may affect breakage. Then, by performing quasi-static compression and dynamic impact experiments under different values of Dp and MC, the detailed compression failure force, rice strength, breakage modes, breakage probability, and the breakage probability models were analyzed comprehensively. Furthermore, breakage processes of rice particles under these two breakage experiments were compared and discussed. Finally, the Weibull distribution of the compression breakage characteristics, the “non-size effect” of compression and impact breakage, the tensile failure forms, velocity threshold of impact breakage and the close relationship between the breakage characteristics under impact and compression were mainly found. The findings are useful for providing guidance for the revelation of breakage mechanism and optimizing related agricultural equipment design.

One of the major advantages of using glass fiber-reinforced polymer bars as a replacement to the traditional steel-reinforced bars is its lightweight and high-resistant to corrosion. This research focuses on the performance of concrete beams partially/fully reinforced with glass fiber-reinforced polymer bars with 50% of GFRP bars were used to reinforce partially concrete beams at flexural zone. While 100% of GFRP bars were used to reinforce fully concrete beams at flexural and compression zones with different concrete compressive strength.This study reported the test results of 6 reinforced concrete beams with dimensions 150 × 200mm and a 1700-mm clear span length subjected to a four-point loading system. The tested beams were divided into three groups; the first one refers to the glass fiber-reinforced polymer bar effect. The second group is referring to the effect of concrete compressive strength, while the third group is referring to the effect of the GFRP bar volume ratio.Using longitudinal GFRP bars as a full or partial replacement of longitudinal steel bar reinforcement led to an increase in the failure load capacity and the average crack width, while a decrease in ductility was reported with a lower number of cracks. Increasing the concrete compressive strength is more compatible with GFRP bar reinforcement and enhanced the failure performance of beams compared with normal compressive strength concrete.

Honeycomb is widely used because of its excellent energy absorption characteristics during compression. However, offset defects in the manufacturing process are inevitable and affect the energy absorption characteristics. In order to study the effect of offset defect, the finite element model was established firstly. The verified finite element model was used to simulate the honeycomb structure under different offsets. The simulation shows that with the increase of the offset λ, the deformation mode of the honeycomb can be divided into three stages and the platform strength increased first and then decreased, and the decrease was obviously greater than the increase. Then the theoretical calculation formula of platform strength of the honeycomb under offset defect was obtained by simple folding theory. The results show that for commonly used honeycomb specifications, when λ = 0.4, the platform strength increases the most, which is 7.99%, and when λ = 1.0, the platform strength decreases the most, which is 18.03%. The theoretical results are similar to the simulation results. For Y-shaped element, the errors are 2.13% and 2.04% at λ = 0.4 and 1.0 respectively, for whole honeycomb, the errors are 0.29% and 4.82% at λ = 0.4 and 1.0 respectively. Therefore, the platform strength of honeycomb can be improved by increasing the offset appropriately.

This paper mainly focused on the mechanical properties of steel reinforced concrete (SRC) T-shaped columns subjected to axial compression in high temperature. A test program consisting of 8 SRC T-shaped columns was carried out at different influence of specimen parameters. The investigated parameters included axial load ratio, loading eccentricity, loading angle, stirrup spacing and steel ratio. The test results showed that: (1) The failure of axial compression specimens was mainly compression failure. However, the failure of eccentric compression specimens became flexural failure due to the loading eccentricity and loading angle. (2) The fire resistance decreased 50.8% with increasing axial load ratio from 0.2 to 0.6. Decreasing steel ratio from 6.9% to 6.0% led to a decline of 39.4% in the fire resistance. The fire resistance of specimens varied only 1.2% for stirrup spacing from 200 mm to 300 mm. (3) The fire resistance of eccentric compression specimens decreased 8.8%～46.2% compared with the axial compression specimens. The fire resistance of specimens decreased 12.9% with the increase of loading eccentricity from 0 to 40 mm. The fire resistance of specimens decreased 46.2% with the increase of loading angle from 0° to 90°. (4) The influence of axial load ratio and loading angle on the fire resistance was much greater than loading eccentricity. Finally, the fire resistance model of specimens in fire was proposed, and the spatial distribution of fire resistance under the action of two factors was presented, which provided a reference for the post-fire assessment of SRC columns.

Natural spinal tissues have unique dynamic properties and it is crucial to investigate the full dynamic response of spinal implants and related biomedical materials to ensure compatibility with the host tissue. Silicon nitride is a promising bioceramic for spinal implants. In this study, the mechanical properties and dynamic response of silicon nitride were comprehensively evaluated using novel and efficient testing methods, at both the material and structural level. The correlation between mechanical properties and porosity was investigated and the results showed that Young's modulus and compressive strength decreased non-linearly as porosity increased. Both the compressive strength (100.35±3.39MPa) and fracture toughness (1.06±0.06MPa⋅m1/2) of the porous silicon nitride samples (~70% porosity) can be considered sufficient for load bearing purposes as a substitute for trabecular bone. Moreover, the results from a drop tower test showed that the average ultimate strength of the scaffolds under an impact loading was significantly lower than the strength under quasi-static compression. Nevertheless, this value is still comparable to that of trabecular bone. Regarding damping capacity, the results of free damped vibration tests of cantilever beams showed that a silicon nitride beam has a higher damping ratio (0.17%±0.01%) than a zirconia beam (0.13%±0.01%), which indicates that ceramics with similar Young's moduli can have different energy dissipating capacities. However, both dense and porous silicon nitride showed a low energy dissipation, substantially lower than natural spinal tissues. Overall, dense silicon nitride possesses a high stiffness, and altering the porosity of silicon nitride is one option to tailor its mechanical properties towards those of trabecular bone, however, more effort is required to increase its damping capacity, if this is a desired trait., Ceramics International, 47 (23), ISSN:0272-8842, ISSN:1873-3956

For typical aerospace alloys, the mechanical properties of TC4 titanium alloy and 7075 aluminum alloy at different loading rates were investigated by uniaxial tension and compression experiments. The fracture microscopic morphologies of the two alloys were compared and analyzed using a scanning electron microscope. In addition, the experiment also combined infrared thermography technology (IRT) to compare and analyze the temperature variation characteristics of TC4 titanium alloy specimens under the same tensile and compressive loading rates. The research results show that the mechanical properties of TC4 titanium alloys are superior to those of 7075 aluminum alloys under the same tensile and compressive loading rates. Constitutive equations considering power-law hardening and tensile loading rate were derived to express the yield flow stress behavior.

As an eco-friendly inorganic cementitious matrix material, a geopolymer mortar combined with short-cut fibers and fiber meshes represents a novel strengthening system, which has been proven to be effective in strengthening existing concrete structural members. However, the behavior of cement concrete cylinders confined by fabric-reinforced geopolymer mortar (FRGM) under compression is unclear. Therefore, in this work, experimental studies were performed to investigate the effects of the number of strengthening layers, matrix strength of the strengthening system, and loading path on the compressive behavior of basalt–FRGM-confined concrete. The experimental results show that two or three layers of the FRGM jacket can help substantially improve the peak stress and its corresponding axial deformation, ductility, and energy absorption ability. The envelope of the cyclic stress–strain curve is consistent with the monotonic stress–strain curve of an identical group of specimens with the same confinement. The residual plastic strain increases with repeated loading cycles, whereas the new reloading stress deteriorates. Regression models are proposed to predict the peak stress and corresponding axial strain in the basalt-FRGM-confined concrete. Finally, monotonic and hysteretic constitutive models for the FRGM-confined cement concrete are developed and compared with the experimental curves. The experimental results provide new insights into the strengthening properties of geopolymer composites and theoretical support for their application. Notably, geopolymer composites can be used in repairing aging and damaged concrete structures while ensuring a low carbon footprint.