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The study utilized the theory of interionic potentials and included analytical functions to account for the volume-dependent short-range force constant. Specifically, a modified version of the Shanker equation of state was used, and expressions were established for isothermal bulk modulus and its pressure derivatives. The researcher extensively analyzed the bismuth ferrite (BiFeO 3 ) material at pressures up to 10 GPa. The result obtained by the newly derived equation of state is compared against previously obtained equations of state, including the Shanker and Vinet equation of state and experimental data. Graphical representations demonstrate the changes in pressure, bulk modulus, and pressure derivative of bulk modulus with compression. The result shows that the newly developed equation of state provides superior outcomes compared to the Shanker and Vinet equations, particularly at high compression levels, due to the inclusion of higher-order compression terms.

Knowledge of pressure-dependent static and dynamic moduli of porous reservoir rocks is of key importance for evaluating geological setting of a reservoir in geo-energy applications. We examined experimentally the evolution of static and dynamic bulk moduli for porous Bentheim sandstone with increasing confining pressure up to about 190 MPa under dry and water-saturated conditions. The static bulk moduli (Ks) were estimated from stress–volumetric strain curves while dynamic bulk moduli (Kd) were derived from the changes in ultrasonic P- and S- wave velocities (~ 1 MHz) along different traces, which were monitored simultaneously during the entire deformation. In conjunction with published data of other porous sandstones (Berea, Navajo and Weber sandstones), our results reveal that the ratio between dynamic and static bulk moduli (Kd/Ks) reduces rapidly from about 1.5 − 2.0 at ambient pressure to about 1.1 at high pressure under dry conditions and from about 2.0 − 4.0 to about 1.5 under water-saturated conditions, respectively. We interpret such a pressure-dependent reduction by closure of narrow (compliant) cracks, highlighting that Kd/Ks is positively correlated with the amount of narrow cracks. Above the crack closure pressure, where equant (stiff) pores dominate the void space, Kd/Ks is almost constant. The enhanced difference between dynamic and static bulk moduli under water saturation compared to dry conditions is possibly caused by high pore pressure that is locally maintained if measured using high-frequency ultrasonic wave velocities. In our experiments, the pressure dependence of dynamic bulk modulus of water-saturated Bentheim sandstone at effective pressures above 5 MPa can be roughly predicted by both the effective medium theory (Mori–Tanaka scheme) and the squirt-flow model. Static bulk moduli are found to be more sensitive to narrow cracks than dynamic bulk moduli for porous sandstones under dry and water-saturated conditions.

Lattice-based metamaterials have attracted much attention due to their excellent mechanical properties. Nevertheless, designing lattice materials with desired properties is still challenging, as their mesoscopic topology is extremely complex. Herein, the bidirectional evolutionary structural optimization (BESO) method is adopted to design lattice structures with maximum bulk modulus and elastic isotropy. Various lattice configurations are generated by controlling the filter radius during the optimization processes. Afterwards, the optimized lattices are fabricated using Stereo Lithography Appearance (SLA) printing technology. Experiments and numerical simulations are conducted to reveal the mechanical behavior of the topology-optimized lattices under quasi-static compression, which are compared with the traditional octet-truss (OT) and body-centered cubic (BCC) lattice structures. The results demonstrate that the topology-optimized lattices exhibited superior mechanical properties, including modulus, yield strength, and specific energy absorption, over traditional OT and BCC lattices. Moreover, apart from the elastic modulus, the yield stress and post-yield stress of the topology-optimized lattice structures with elastically isotropic constraints also present lower dependence on the loading direction. Accordingly, the topology optimization method can be employed for designing novel lattice structures with high performance.

The blisk surface roughness has a significant impact on its fatigue strength and service life. It is very meaningful to study the influence factors of blisk surface roughness. In this paper, a calculation model for the bulk modulus of abrasive cloth wheel is deduced, the values of bulk modulus of abrasive cloth wheel corresponding to different process parameters are obtained by experiment, and a mathematical model of polished surface roughness about bulk modulus of abrasive cloth wheel is established. By verification, it is found that the model of polished surface roughness can accurately predict the blade surface roughness after polishing. The model has guiding significance for improving polishing process and machining quality.

HighlightsLaboratory experiments were designed to measure Skempton coefficient B for Dunnville sandstone using small and large specimens.The pore volume Vp of the small specimen was on the same order as the system volume Vl, while Vp of the large specimen was 100 times Vl.The large specimen provided a direct measurement of B.For Dunnville sandstone, Skempton coefficient B calculated with the appropriate poroelastic model and material parameters agrees with the measured B.

This research paper presents a comprehensive theoretical analysis of the bulk modulus, pressure derivative of bulk modulus, and Grüneisen parameter in superconductors. The study aims to elucidate the fundamental properties governing the mechanical behavior of superconducting materials under various external pressures and to check the applicability of various EOSs. Through rigorous calculations and theoretical modeling, we explore the relationship between these parameters and their impact on the overall performance of superconductors. By employing advanced theoretical frameworks and first-principles calculations, we determine the bulk modulus, a measure of material's resistance to compression, as well as the pressure derivative of bulk modulus, which quantifies the response of the material's bulk modulus to changes in external pressure. Additionally, we investigate the Grüneisen parameter, which characterizes the influence of thermal expansion on the material's mechanical properties. The findings of this research shed light on the fundamental mechanical properties of superconductors and provide valuable insights into their behavior under varying external pressures. The obtained results contribute to the fundamental understanding of superconductivity and offer potential avenues for optimizing the design and performance of superconducting materials in diverse applications ranging from energy transmission to quantum computing. Stacey criterion and available experimental and theoretical work will validate our work.

Fiberboards from scrap denim were fabricated using two different resins, melamine urea formaldehyde (MUF) and polymeric methylene diphenyl diisocyanate (pMDI). Resin content and MUF-pMDI weight ratio were studied. Physical and mechanical tests determined the modulus of elasticity (MOE), modulus of rupture (MOR), internal bond (IB), thickness swell (TS), and water absorption (WA). The resin content had significant impact on all properties. The MOE and IB were affected by the MUF-pMDI ratio. With 17 wt% more pMDI resin portion in the core layer of the denim boards, the IB for the denim fiberboard with a resin content of 15% was enhanced by 306%, while by 205% for the resin content of 25%. The increase in pMDI portion in the core layer of the boards improved both TS and WA of the scrap denim fiberboard. Effective bulk modulus elastography (EBME) was used to measure the acoustic reflection for the estimation of the strength properties of the denim fiberboard. The modulus results from EBME were correlated to the MOR, MOE, and IB of the denim fiberboard. A high correlation was found between the modulus from EBME and IB (R2 > 0.98). EBME can be a great technique to evaluate the bulk modulus distribution of the composites.

Isostatic pressure effects on the elastic and electronic properties of non-doped and Mn4+-doped K2SiF6 (KSF) have been investigated by first-principles calculations within density functional theory (DFT). Bulk modulus was obtained by the Murnaghan’s equation of states (EOS) using the relationship between volume and pressures at pressures between 0 and 40 GPa, and elastic constants were calculated by the stress–strain relationship giving small distortions at each pressure point. The other elastic parameters such as shear modulus, sound velocity and Debye temperature, which can be obtained from the elastic constants, were also estimated. The influence of external isostatic pressure on the electronic properties, such as crystal field strength 10Dq and emission energy of 2E → 4A2 transition (Eem), of KSF:Mn4+ was also studied. The results suggest that 10Dq and Eem linearly increase and decrease, respectively, with increasing pressure.

Determination of the mechanical behaviour of intact rock is one of the most important parts of any engineering projects in the field of rock mechanics. The most important mechanical parameters required to understand the quality of intact rock are Young’s modulus (E), Poisson’s ratio (ν), the strength of rock (σc) and the ratio of Young’s modulus to the strength of rock known as modulus ratio (MR), which can be used for calculations. The particular interest of this paper is to investigate the relationship between these parameters for Hungarian granitic rock samples. To fulfil this aim, Modulus of elasticity (E), Modulus of rigidity (G), Bulk modulus (K) and the modulus ratio (MR = E/σc) of 50 granitic rock samples collected from Bátaapáti radioactive waste repository were examined. Fifty high-precision uniaxial compressive tests were conducted on strong (σc > 100 MPa) rock samples, exhibiting the wide range of elastic modulus (E = 57.425–88.937 GPa), uniaxial compressive strength (σc = 133.34–213.04 MPa) and Poisson’s ratio (ν = 0.18–0.32). The observed value (MR = 326–597) and mean value of MR = 439.4 are compared with the results of similar previous researches. Moreover, the statistical analysis for all studied rocks was performed and the relationship between MR and other mechanical parameters such as maximum axial strain (εa, max) for studied rock samples was discussed. Finally, the validity of the proposed mathematical model by Palchik (Geomech Geophys Geo-energy Geo-resour 6:1–12, 2019) for stress–strain behaviour of granitic rock samples was investigated.

This study focuses on the development of a computational fluid dynamics (CFD) model using Ansys Fluent to predict maximum pressure and pressure changes over time. The accuracy of hydraulic modeling is directly influenced by the bulk modulus of hydraulic oil, making it a crucial characteristic to study. Experimental data was used to validate the results obtained from the CFD model. Furthermore, an in-depth investigation was conducted to analyze the fluid bulk modulus and its correlation with the presence of air trapped inside the cylinder. The findings of this research provide valuable insights into the behavior of hydraulic systems and the importance of accurate fluid property characterization for effective modeling.