Material Properties Of Matrix Research Articles

A force-density framework for flexible multi-body dynamic analysis of clustered tensegrity structures

This paper develops a versatile and effective force-density framework for the flexible multi-body dynamic analysis of clustered tensegrity structures. In this framework, the force density is selected as the basic variable instead of force, and the clustered tensegrity structure is mathematically described in a vector and matrix form, encompassing topology, geometry, material, and force properties. A non-negative variable is defined as an indicator of the member stress state, and a complementary function is constructed to address the discontinuity issues that arise from the unidirectional axial stiffness of cables. Dynamic formulas are established within this force-density framework, with nodal coordinates selected as generalized parameters and formulations constructed in a matrix form. A complementary framework is established as an alternative for solving the dynamic equations, transforming the isolated steps of Newton’s iteration and cable state judgment (slack or tension) into a unified one, bringing more potential for improving solving efficiency. Numerical simulations are carried out to validate the approach, demonstrating that it effectively reveals the dynamic oscillation, tension changes, and cable slack behavior of clustered tensegrity structures during shape control. Comparative studies highlight the advantage of computational efficiency. The method proposed in this paper provides a robust mathematical model for studying clustered tensegrity structures, particularly regarding the shape control of deployable, active, and intelligent structures, aiding in understanding dynamic oscillation, tension changes, and cable slack behavior during their deformation. The methods can also be applied to cable net structures and other prestressed pin-jointed systems.

Removal mechanism and hole quality of SiCp/Al composites by ultrasonic elliptical vibration-assisted helical milling

SiCp/Al composites are widely used in the aerospace field due to their excellent properties. However, the huge difference in the properties of silicon carbide and aluminum matrix materials can easily lead to machining defects. Ultrasonic vibration-assisted machining is an effective method to deal with difficult-to-machine materials. In this study, ultrasonic elliptical vibration is applied to the helical milling of SiCp/Al composites. Firstly, the ultrasonic elliptical vibration-assisted helical milling (UEVHM) cutting-edge trajectory is modeled, and the equation of the UEVHM tool-chip separation condition is established, which lays a foundation for the analysis of the cutting mechanism. Then, the influence of ultrasonic elliptical vibration on the removal mechanism of SiCp/Al composites was investigated by finite element simulation. It was found that UEVHM can reduce the tearing of aluminum matrix and reduce the hole damage by changing the direction of the cutting velocity and the relative position of the cutting edge and particles. Finally, the single-factor experiment was carried out, and the surface morphology and roughness of HM and UEVHM were compared. The influence of process parameters on the surface roughness of UEVHM was analyzed. The experimental results show that compared with HM, UEVHM can reduce surface defects and exit damage, to obtain better surface roughness and exit edge quality. The increase in cutting speed can reduce the roughness, and the increase in pitch and revolution speed will increase the surface roughness.

Peridynamics-based model of composite lamina with progressive variations in mechanical properties

An analytical model of the fiber-reinforced composite lamina is constructed based on bond-based peridynamics (PD), which utilizes variable matrix bonds and fiber bonds to evaluate the static properties of matrix and fiber materials, respectively. The bond stiffness of the matrix is determined by trigonometric functions, and fibers are represented by constants. The proposed PD model describes the continuous variations in the static properties of composites as a function of fiber angle. Both the conventional analytical method and the PD method are used to solve the failure-free elastic deformation issue. The two methods estimate maximum errors in the displacement of material points in the x and y directions of 0.01 % and 4.86 %, respectively, indicating good consistency. The failure propagation of the preexisting crack layer under the axial tensile load is simulated and the obtained failure modes are in good agreement with experimental results. The proposed composite lamina model simulates the influence of fiber direction on overall behavior through various matrix bond stiffness. Breaking through the limitation of constant matrix bond stiffness in conventional models, is conducive to promoting the further development of bond-based composite PD models.

Bone matrix properties in adults with osteogenesis imperfecta are not adversely affected by setrusumab-a sclerostin neutralizing antibody.

Osteogenesis imperfecta (OI) is a skeletal dysplasia characterized by low bone mass and frequent fractures. Children with OI are commonly treated with bisphosphonates to reduce fracture rate, but treatment options for adults are limited. In the Phase 2b ASTEROID trial, setrusumab (a sclerostin neutralizing antibody, SclAb) improved bone density and strength in adults with type I, III, and IV OI. Here, we investigate bone matrix material properties in tetracycline-labeled trans iliac biopsies from 3 groups: (1) control: individuals with no metabolic bone disease, (2) OI: individuals with OI, (3) SclAb-OI: individuals with OI after 6 mo of setrusumab treatment (as part of the ASTEROID trial). In addition to bone histomorphometry, bone mineral and matrix properties were evaluated with nanoindentation, Raman spectroscopy, second harmonic generation imaging, quantitative backscatter electron imaging, and small-angle X-ray scattering. Spatial locations of fluorochrome labels were identified to differentiate inter-label bone of the same tissue age and intra-cortical bone. No difference in collagen orientation was found between the groups. The bone mineral density distribution and analysis of Raman spectra indicate that OI groups have greater mean mineralization, greater relative mineral content, and lower crystallinity than the control group, which was not altered by SclAb treatment. Finally, a lower modulus and hardness were measured in the inter-label bone of the OI-SclAb group compared to the OI group. Previous studies suggest that even though bone from OI has a higher mineral content, the extracellular matrix (ECM) has comparable mechanical properties. Therefore, fragility in OI may stem from contributions from other yet unexplored aspects of bone organization at higher length scales. We conclude that SclAb treatment leads to increased bone mass while not adversely affecting bone matrix properties in individuals with OI.

High-fat and high-carbohydrate diets increase bone fragility through TGF-β-dependent control of osteocyte function.

Obesity can increase the risk of bone fragility, even when bone mass is intact. This fragility stems from poor bone quality, potentially caused by deficiencies in bone matrix material properties. However, cellular and molecular mechanisms leading to obesity-related bone fragility are not fully understood. Using male mouse models of obesity, we discovered TGF-β signaling plays a critical role in mediating the effects of obesity on bone. High-carbohydrate and high-fat diets increase TGF-β signaling in osteocytes, which impairs their mitochondrial function, increases cellular senescence, and compromises perilacunar/canalicular remodeling and bone quality. By specifically inhibiting TGF-β signaling in mouse osteocytes, some of the negative effects of high-fat and high-carbohydrate diets on bones, including the lacunocanalicular network, perilacunar/canalicular remodeling, senescence, and mechanical properties such as yield stress, were mitigated. DMP1-Cre-mediated deletion of TGF-β receptor II also blunted adverse effects of high-fat and high-carbohydrate diets on energy balance and metabolism. These findings suggest osteocytes are key in controlling bone quality in response to high-fat and high-carbohydrate diets. Calibrating osteocyte function could mitigate bone fragility associated with metabolic diseases while reestablishing energy balance.

Simple double shooting approach with bisection for FRCM reinforced curved masonry prisms subjected to shear

In this study, curved masonry pillars reinforced with FRCM subjected to standard shear tests are analyzed through a novel mono-dimensional model, where failure is governed by Mode II. Three approaches with different accuracy are proposed: i) the first, where the outer matrix is neglected; ii) the second, where the inner matrix is assumed rigid; and iii) the third which considers both matrix layers. Matrix and fiber are assumed subjected to a monoaxial state of stress and exchange tangential stresses at the interfaces. The load is applied by incrementing the displacement at the free fiber edge. Material properties of matrix, fiber and interfaces are assumed constant on small portions of the bonded length. Non-linearity is considered penalizing the elastic modulus using the results of the previous time step. The substrate is assumed rigid. The substrate curvature influence is manifested through interface normal stresses, incorporated into the bond-slip constitutive behavior via the Mohr-Coulomb law. The normal stresses can be determined by enforcing radial equilibrium. For the first two models, the field problem is constituted by a system of two 2nd order differential equations into two variables, namely the displacement of the inner (or outer) layer of mortar and of the fiber textile. A 1D shooting is employed, after having converted the boundary value problem (BVP) into an initial value one (IVP), being the latter fully explicit. For the third model, the field problem is constituted by a system of three 2nd order differential equations, and an additional displacement variable is introduced, necessitating a 2D shooting. The validation is carried out through comparisons with existing experimental data. Good predictions of the load-slip curves, for different strengthening configurations (extrados and intrados with two curvature radii), are observed. In addition, an insight into local stress distributions and material degradation for matrix layers and interfaces is obtained.

Stretchable-thickness model for dynamic responses of graphene origami reinforced badminton sport plate

In this article, we organize a stretchable-thickness model to present a frequency analysis for a composite plate applicable in badminton court which is reinforced with origami graphene. A higher order kinematic model is extended in this work including three bending, shear, and stretching functions, where the stretching functions is responsible for satisfying the out of plane shear strains and stresses at top/bottom surfaces of the badminton equipment. The sport or composites plate is manufactured from a copper matrix reinforced with graphene origami where the effective material properties are calculated based on micromechanical models as a function of volume fraction and folding degree of graphene origami, material properties of matrix and reinforcement and temperature. The numerical results are presented with changes of volume fraction, folding degree of reinforcement, and thermal loading along the thickness direction. The main novelty of this work is accounting thickness stretching deformation for the analysis of a graphene origami reinforced plate and investigating the responses of graphene origami as a new reinforcement. A verification investigation is presented for approve of the methodology, and solution procedure. An investigation on the order of deformation is presented for various thickness ratio of the badminton sport plate.

Analysis of sandwich graphene origami composite plate sandwiched by piezoelectric/piezomagnetic layers: A higher-order electro-magneto-elastic analysis

This work applies a higher order thickness-stretched model for the electro-elastic analysis of the composite graphene origami reinforced square plate sandwiched by the piezoelectric/piezomagnetic layers subjected to the thermal, electric, magnetic and mechanical loads. The plate is manufactured of a copper matrix reinforced with graphene origami where the effective material properties are calculated based on the micromechanical models as a function of volume fraction and folding degree of graphene origami, material properties of matrix, reinforcement, and local temperature. The governing equations are derived using the virtual work principle in terms of the bending, shear and stretching functions, in-plane displacements, electric, and magnetic potentials. The numerical results including various displacement components, maximum electric, and magnetic potentials are presented with changes of volume fraction, folding degree of reinforcement, electrical, magnetic, and thermal loading. A verification investigation is presented for approve of the methodology, and the solution procedure. The main novelty of this work is simultaneous effect of the thickness stretching and the multi-field loading on the electromagnetic bending results of the sandwich plate. Another novelty of this work is usage of graphene origami nano-reinforcement as a controllable material in a sandwich structure subjected to multi-field loadings. The results show an increase in bending, shear, and stretching deflections with an increase in electromagnetic loads, and folding degree as well as a decrease in volume fraction of reinforcement.

A Metastructure Based on Amorphous Carbon for High Efficiency and Selective Solar Absorption.

Efficient solar thermal conversion is crucial for renewable clean energy technologies such as solar thermal power generation, solar thermophotovoltaic and seawater desalination. To maximize solar energy conversion efficiency, a solar selective absorber with tailored absorption properties designed for solar applications is indispensable. In this study, we propose a broadband selective absorber based on amorphous carbon (a-C) metamaterials that achieves high absorption in the ultraviolet (UV), visible (Vis) and near-infrared (NIR) spectral ranges. Additionally, through metal doping, the optical properties of carbon matrix materials can be modulated. We introduce Ti@a-C thin film into the nanostructure to enhance light absorption across most of the solar spectrum, particularly in the NIR wavelength band, which is essential for improving energy utilization. The impressive solar absorptivity and photothermal conversion efficiency reach 97.8% and 95.6%, respectively. Notably, these superior performances are well-maintained even at large incident angles with different polarized states. These findings open new avenues for the application of a-C matrix materials, especially in fields related to solar energy harvesting.

Free vibration analysis of graphene origami-reinforced nano cylindrical shell

Vibrational behavior of a shear deformable cylindrical shell is studied in this article based on Hamilton’s principle. The shell is manufactured by a Copper (Cu) core reinforced with graphene origami auxetic metamaterial and subjected to mechanical and thermal loads. The constitutive relations are developed based on the shear deformable model where the effective modulus of elasticity, Poisson’s ratio, and density are evaluated using micromechanical models including volume fraction and folding degree of graphene origami auxetic metamaterial, geometric characteristics of graphene, material properties of matrix, and reinforcement and local temperature. The natural frequencies are obtained based on Navier’s and Galerkin’s approaches for simply supported, clamped-simply, and clamped-clamped boundary conditions. The formulation, solution procedure, and numerical results are confirmed through comparison with the available results of the literature. The complete numerical results are presented in terms of volume fraction and folding degree of graphene origami auxetic metamaterial, thermal loading, and various types of boundary conditions.

Electro-elastic results of graphene origami-reinforced sandwich doubly curved shells

Static electroelastic behavior of a doubly curved shell composed of copper core reinforced with graphene origami auxetic metamaterial are studied in the present paper. The shell is subjected to uniform mechanical, electrical and thermal loads. To evaluate effective material properties, the micromechanical models are extended in terms of both material properties of matrix and reinforcement with changes of temperature, volume fraction, folding degree and geometric parameters of graphene nanoplatelets. After extension of energy method using piezoelasticity relations, the governing equations are analytically solved and the then the analytical solution is derived to explore importance of foldability and multifield loading on the responses. After that the comprehensive results are obtained with changes of thermal loading, graphene amount, folding degree, geometric characteristics and foundation’s parameter.

4D printed zero Poisson’s ratio metamaterials with vibration isolation properties for magnetic response

Although mechanical metamaterials possess high specific energy absorption, they suffer from drawbacks such as irreversible deformations and non-adjustable mechanical properties. Magnetic excitation is considered to be one of the most promising methods for special working environments; for which uniform incorporation of UV-cured four-dimensional (4D) printed resin is considered to be an effective approach to achieving fine structural features. Our study investigated the impact of soft magnetic particle content on the mechanical and dynamic mechanical properties of a shape memory polymer matrix material. This paper presents a 4D printed metamaterial with a zero Poisson’s ratio that can sense magnetic field intensity and alter its mechanical properties. Its rapid shape recovery, achieved through magnetic excitation, enables multiple energy absorption within a short timeframe. By increasing the curvature radius, the stress concentration in the hexagonal honeycomb structure is reduced, ensuring the metamaterial maintains its zero Poisson’s ratio even under in-plane loading. The study investigates the energy absorption performance and force–displacement curve of metamaterials with different layers and cell sizes, focusing on a four-layer metamaterial for the analysis. Furthermore, the paper explores the tunable energy absorption characteristics of the four-layer metamaterial under time-varying electromagnetic fields, aiming to enhance the stability of a lander’s center of gravity while landing on uneven terrain.

An accurate semi-analytical method for the treatment of an eccentric annular crack embedded in an infinite isotropic elastic medium under arbitrary internal pressure

This work provides a semi-analytical method for the calculation of the stress intensity factor (SIF) associated with an internally pressurized eccentric annular crack embedded in an infinite isotropic elastic solid. The inner and outer edges of the crack consist of the circumferences of two eccentric circles and the internal pressure exerted on the crack faces has an arbitrary distribution. Using Somigliana formulation a hypersingular integral equation governing the proposed crack problem is obtained. Next, by the employment of a conformal mapping the considered crack is mapped on to a concentric annular crack. In the mapped domain, with the aids of Fourier expansion of the displacement discontinuity function across the crack faces together with the notion of the Hadamard finite-part integral, the hypersingular integral equation is converted to a system of linear algebraic equations for the unknown constants of the expansion. Upon the determination of these constants, the angular dependent SIFs along both the inner and outer edges of the crack are obtained accurately. The accuracy of the current formulation is showcased through the re-examination of the simple concentric annular crack problems considered previously in the literature. In the presence of eccentricity, the effects of such geometrical parameters as the ratio of the radii of the inner to outer eccentric circular edges of the crack and the normalized eccentricity on the values of the SIFs along both the inner and outer edges of the crack are studied. As it will be seen the material properties of the elastic matrix do not affect the values of SIFs.

Matrix-Material Fabrication Technique and Thermogravimetric Analysis of Banana Fiber Reinforced Polypropylene Composites

From the environmental consideration, it would be very interesting to use natural fibers such as banana, jute or coir as reinforcement materials instead of artificial fibers or any kind of synthetic materials. Natural fibers have many advantages over synthetic ones. Polypropylene banana fiber composites (PPBC) are prepared using untreated and alkalitreated banana fibers at 10-25% by weight of the fiber loading. The thermal properties of polypropylene natural fiber composites are very important for technological uses. Thermogravimetric measurements show that the incorporation of banana fiber into PP enhances the thermal stability of composites containing treated fibers, in comparison with untreated fibers. A composite of biodegradable polypropylene (PP) reinforced with short banana natural fibers was prepared by melt blending followed by a hot press molding system. The thermal properties of matrix materials were studied using thermogravimetric analyzers TGA units. It is observed that the introduction of short banana fibers slightly improved the thermo oxidative stability of PP-banana composites. Physical and chemical changes occurred through dehydration, phase transition, molecular orientation, crystallinity disruption, oxidation and decomposition, and incorporation of several functional groups. Systematic investigations of the thermal behavior of polymers in gas, vacuum or inert atmosphere give the knowledge of how change takes place in polymers. To understand such changes thermogravimetric analysis (TGA) and thermal analysis (TG) were performed. It is observed reinforcement of short banana fiber leads to little improvement in the thermooxidative stability of PPBC. Due to the enhancement of thermo-mechanical properties, such composites may be used as building materials namely roof materials, selling materials and many other engineering applications.

The Catalytic Curing Reaction and Mechanical Properties of a New Composite Resin Matrix Material for Rocket Fuel Storage Tanks

In this paper, an equimolar blend of bisphenol A dipropargyl ether and cyanate ester was selected to study the effect of different catalysts on the curing reaction of a bisphenol A dipropargyl ether and cyanate ester blended resin system, and the thermal stability and mechanical properties of the catalytically cured blended resin system were investigated. Acetylacetone salts of transition metals and dibutyl ditin laurate reduced the curing temperature of bisphenol AF-type di cyanate ester, and copper acetylacetonate at a mass fraction of 0.3% significantly reduced the curing temperature of bisphenol AF-type di cyanate ester to less than 473 K. Bisphenol A dipropargyl ether pr-polymerized and equimolarly blended with bisphenol A di cyanate ester and bisphenol E-type di cyanate ester also cured below 473 K under the same conditions. Among the cured compounds of the blended resins of bisphenol A dipropargyl ether with bisphenol AF-type di cyanate ester, bisphenol A-type di cyanate ester and bisphenol E-type di cyanate ester, the blended resins of bisphenol A-type di cyanate ester and bisphenol E-type di cyanate ester have better overall performance. The residual rate of 873 K in air was 38%, and the flexural strength, flexural modulus, and impact strength were 129.4 MPa, 4.3 GPa, and 27.3 kJ·m−2, respectively. This kind of blended resin is expected to be used in the liquid oxygen storage tanks of rockets.

Interfacial strength characteristics between modified iron tailings and profiled fibers under dry–wet and freeze–thaw environments

The interfacial properties of fibers and matrix materials have an important effect on the mechanical properties of fiber-reinforced materials. To study the role of fiber morphology and the environmental effects on the interfacial properties of fibers and matrix materials, the interfacial strength characteristics of undulation polypropylene fiber (UPF) and serrated polypropylene fiber (SPF) with cement-modified iron tailings (CIT) were analyzed through single-fiber pullout tests. The effects of curing age, freeze–thaw cycles, and dry–wet cycles on interfacial strength were analyzed. The energy dissipation during fiber pullout under different environmental conditions was verified, and the microscopic mechanism of interfacial strength change was determined. The results show the following: (1) The interfacial strength of UPF and SPF is positively correlated with curing age, while freeze–thaw and dry–wet cycles can impair their interfacial properties; also, the interfacial strength decreases substantially and tends to flatten out after 3 cycles. (2) The dissipation energy of UPF and SPF increases with curing age, but decreases as the number of dry–wet cycles and freeze–thaw cycles increases. The critical reinforcement length of UPF is better than that of SPF by 363% and 50% under freeze–thaw and dry–wet cycles, respectively. Also, its performance and reinforcement effect in reducing crack development under freeze–thaw and dry–wet environments are better compared to SPF. (3) The interfacial strength of the profiled fibers consists of adhesion and friction. Freeze–thaw cycles cause a significant damage to adhesion and friction, while dry–wet cycles mainly affect adhesion. Interfacial strength is related to the curvature of the fiber and the unconfined compressive strength of CIT, which follows a linear function.

Finite Element Analysis of Additively Manufactured Continuous Carbon Fiber-Reinforced Composites

AbstractThe objective of this study is to provide a numerical modeling approach for continuous carbon fiber (CCF)-reinforced fused filament fabricated composites. Although these materials have been extensively studied, an effective numerical modeling technique for their mechanical performance does not exist. To fill this technical gap, a numerical modeling approach based on finite element analysis is presented. The effective material properties of the Onyx matrix when voids are present are derived by the Kerner model. The material properties of CCF-reinforced composites are modeled by Hashin’s model. Both the flexural and tensile properties are simulated. The modeling approach is validated against various experimental results.

Global sensitivity analysis of complex moduli of carbon fiber reinforced polymer

AbstractGlobal sensitivity analysis of complex moduli of carbon fiber reinforced polymer (CFRP) is performed by using variance‐based sensitivity analysis. Twelve material properties of matrix and fiber are selected as input arguments, including fiber volume fraction, three matrix properties, and eight carbon fiber properties. Ten thousand samples are generated with Sobol sequence. Based on the correspondence principle, six complex moduli of unidirectional CFRP, and two complex moduli of quasi‐isotropic laminate, orthogonal laminate, and symmetric laminate with different fiber angles are predicted using the generalized method of cells and classical laminate theory. The sensitivity indexes of all input arguments are calculated. The results show that the loss factors of CFRP are mainly affected by the matrix loss factor and fiber axial loss factor, and slightly affected by the fiber transverse loss factor.Highlights Sensitivity analysis reveals key factors influencing CFRP complex moduli. Impact of fiber and matrix properties on CFRP damping revealed. Insights for high‐damping and high‐stiffness CFRP development. Enhanced understanding of energy absorption mechanisms. Uncovering the dominant role of matrix and fiber axial properties in damping.

Thermal contact resistance measurement between two intersecting PAN type carbon fibers using the T-type 3ω method

The prediction of the effective thermal conductivity of composites filled with carbon fibers requires the knowledge of the microstructure, the relative amount and thermal properties of filler and matrix materials, the orientation of non-isometric filler phases and the thermal contact resistances between fibers and matrix and also between fibers. However, information at small scale are often missing especially thermal contact resistances. The present work describes the measurement of the thermal contact resistance (TCR) between two crossed carbon fibers which is performed by an adaptation of the T-type 3ω method for thermal conductivity measurement of wires. The first carbon fiber is connected to two copper blocks supplied by a modulated electrical current providing a volumetric heating. The second fiber fixed on a U-shape holder is delicately implemented over the first one. After performing a secondary vacuum, the 3ω voltage V3ω of the first fiber is recorded as function of the frequency of the modulated current. Knowing the applied force, the contact area between the two carbon fibers is calculated from bending and deformations then a 3D numerical model describing heat transfer in two crossed carbon fibers is used to estimate the TCR at their intersection. In addition, a detailed sensitivity analysis of the unknown parameter TCR is performed allowing to find optimal operating conditions especially the frequency range. Measurements are performed with PAN type carbon fibers (FT300B) picked up from the same bundle. Different TCR estimations were performed by fitting numerical and computed V3ω voltage as function of frequency. Finally, values of TCR between crossed carbon fibers were found equal (10.4 ± 10.1) 105 kW−1 which provides an order of magnitude for such phenomenon.

Data driven statistical method for the multiscale characterization and modelling of fiber reinforced composites

Multiscale analysis of composite laminates allows for predicting the mechanical response of these materials avoiding cumbersome experimental campaigns. The matrix and fibre material properties and the size of the Representative Volume Element (RVE) are the main parameters affecting the accuracy of multiscale models. This paper proposes a statistical inverse method to calibrate micromechanical material parameters from macroscale experiments and 3D reconstruction. First, glass fiber reinforced epoxy laminates have been analysed with Computer Tomography (CT), then, the material 3D microstructure has been reconstructed and fibre, matrix, and voids were segmented. Tensile tests have been performed on the composite specimen, measuring the surface strains with a Digital Image Correlation (DIC) system. The reconstructed volume, converted to a voxel mesh, has been used to compute the homogenized response of composite by Fast Fourier Transform (FFT) analysis. By comparing the marginal distribution of homogenized material stiffness extracted from DIC data of tensile tests, with the conditioned distribution computed by varying the FFT model parameter, a Stochastic Volume Element (SVE) is finally calibrated. A probabilistic multiscale model based on the SVE that propagates the uncertainty from the microscale to the structure level is presented.