Compression Mode Research Articles

Effects of temperature on the anisotropic mechanical properties and failure mechanisms of Sheet Molding Compounds

Sheet Molding Compounds (SMC) are widely used in many industries. Due to their high in-mold flow, fibers tend to align during the component processing and generate anisotropic mechanical properties. Besides, being SMCs thermoset composites, their application in high temperature environments often results to be of interest. In this research, the fiber orientation and temperature-dependent mechanical behavior and failure mechanisms were studied. First, materials were compression molded into plates, promoting fiber orientation. Then, the materials’ orientation-dependent viscoelastic behavior was analyzed by Dynamic Mechanical Analysis, and their anisotropy level was assessed at quasi-static tensile, bending and compression modes at 23 °C and 130 °C. Finally, the failure mechanisms were inspected by confocal microscopy to evaluate the influence of temperature and fiber orientation on them. The results demonstrate how the temperature influences the material’s mechanical performance and their anisotropic behavior, especially at 45°. Likewise, temperature alters failure mechanisms, by triggering the fiber-matrix interface failure.

Compressive behavior of Body-Centered-Cubic (BCC)-like ultra-lightweight Carbon Fiber Reinforced Polymer (CFRP) lattice-based sandwich structures

3D lattice structures comprise a connected network of segments that allow positioning of the base material where needed while maintaining an open-cell characteristic. These structures represent an ideal lightweight core material for high-performance sandwich panels. This work presents, for the first time, the performance of lattice-based cores fabricated via indirect additive manufacturing using pultruded Carbon Fiber Reinforced Polymer (CFRP) rods. The CFRP sandwich panels were tested under out-of-plane compression, and their compressive properties and failure modes were predicted via analytical and FE analyses, later contrasted with mechanical testing. Finally, the study compares favorably with similar core materials found in the literature.

Investigation into microstructure, mechanical properties, and compressive failure of functionally graded porous cylinders fabricated by SLM

As the utilization of additively manufactured (AM) functionally graded porosity (FGP) structures continues to rise in various industries, there is a growing need for a comprehensive understanding of their design, microstructure, mechanical behavior, and failure mechanisms. This study involves the design and fabrication of FGP specimens with an 85 % volume fraction using selective laser melting (SLM) and 316L stainless steel powder, focusing on characterizing porosities, printing quality, and microstructure. Experimental tests, including tensile, quasi-static compression, and Split Hopkinson Pressure Bar tests, are conducted to assess the material behavior. Additionally, finite element analysis (FEA) and experimental compression tests are employed to investigate the compressive mechanical behavior and failure modes of FGP structures. The findings indicate that porosity distribution has minimal impact on the compressive behavior, specific energy absorption (SEA), and toughness of FGP structures. Furthermore, reducing the volume fraction from 85 % to 75 % in the S1FG samples increases the SEA by 7.2 % and changes the toughness by 5.9 %. Notably, porosity distribution influences fracture position and failure mechanisms during compression tests.

A novel “S” chain structure mechanism model of magneto-rheological elastomer

Mechanism models based on chain-like structures are often used to characterize the morphology of magneto-rheological elastomer (MRE) and provide theoretical guidance for MRE preparation. However, widely used shear and tension mechanism models based on oblique straight chain or bent-chain structures have the limitation of insufficient accuracy in characterization, mainly because the internal particle chains of anisotropic MRE are not simple oblique straight or bent from scanning electron microscope (SEM) results. Therefore, the particle chain formation and particle interaction mechanism within MRE are revealed firstly. The theoretical results shows that particles tend to form S-like chain structures due to complex attraction and extrusion. On this basis, a novel “S” chain mechanism model is proposed, which is confirmed to have higher accuracy than the ideal shear model and tension model by comparing with the experimental results. The main reason is that the “S” chain mechanism model has realized the unification of shear, compressive, or tension mode, and integrates the fully coupled magnetic field, distribution parameters and interface stretching. The “S” chain mechanism model also takes into account the radius and volume fraction of the particles in MRE preparation, which makes it a more accurate guide to subsequent preparation.

On energy mechanism of rate-dependent failure mode evolution in plain weave composite

The intricate failure modes and the yet unclear rate dependency of carbon fiber reinforced plain weave composite materials pose a challenge to mechanics researchers. This study establishes an energy-based evolution mechanism for the compressive failure modes of plain weave composite materials as the strain rate varies. This mechanism illustrates how the rate dependency of failure modes arises from the competitive relationship between strain potential energy and deformation kinetic energy. At low loading rates, the specimen exhibits a progressive crushing failure mode characterized by low peak stress and significant geometric deformation. As the loading strain rate increases, the energy required for this geometric deformation also increases. When the energy expenditure surpasses that needed to elevate the stress level of the specimen, it transitions to an instantaneous failure mode with high peak stress. In this mode, the specimen fractures into multiple small fragments immediately upon failure, lacking the large geometric deformations observed at lower rates. Through calculating this energy mechanism, a transition strain rate of 180 s−1 was determined for both failure modes. The accuracy of this mechanism was further verified by tests conducted near the critical strain rate. The energy-based evolution mechanism for failure modes provides a simplified and concise framework for simplifying complex models of composite material failures.

Spatio-Temporal Compressive Behaviors of River Pebble Concrete and Sea Pebble Concrete in Island Offshore Engineering

Obtaining river or sea pebbles from local resources for concrete production is considered an economical and eco-friendly alternative, particularly in marine and island-offshore engineering. However, the resulting changes in the mechanical properties of these concrete have attracted attention. This study investigates the compressive behavior of concretes where river or sea pebbles partially (i.e., 33% and 67%) or fully (i.e., 100%) replace traditional gravel as coarse aggregate, using a noncontact full-field deformation measurement system based on digital image correlation (DIC). Compared to the traditional gravel concrete (GC), compressive strengths of the river pebble concrete (RPC) at constitution rates of 33%, 67%, and 100% decreased by 6.5%, 29.8%, and 38.9% while those values of the sea pebble concrete (SPC) decreased by 13.1%, 32.7%, and 44.3%, respectively. Meanwhile, SPC exhibited slightly lower compressive strength than RPC. The peak strains of both SPC and RPC decreased at lower substitution rates, although their stress-strain curves resembled those of GC. In contrast, RPC and SPC at higher substitution rates exhibited a noticeable stage of load hardening. Full-field deformation data and interfacial characteristics indicated that the compressive failure modes of both RPC and SPC showed significant interfacial slipping between pebbles and mortar with increasing coarse aggregate substitution rates. In comparison, fractures in coarse aggregate and mortar were observed in damaged GC. The study demonstrated that the spatio-temporal compressive deformation response and failure modes of SPC and RPC were distinct due to the introduction of pebbles, providing insights for engineering applications of river/sea pebble concrete in practical offshore or island construction projects.

A comparative study on mechanical-electrical-thermal characteristics and failure mechanism of LFP/NMC/LTO batteries under mechanical abuse

Understanding the failure behaviors and failure mechanisms of lithium-ion batteries under mechanical abuse is essential for numerical reconstruction of abuse scenarios for different types of cells. This study investigates the mechanical-electrical-thermal characteristics, components tensile properties and failure mechanisms of LiFePO4 (LFP), Li(Ni0.5Mn0.3Co0.2)O2 (NMC), and Li2TiO3 (LTO) cells through indentation experiments, including ball intrusion, cylindrical intrusion, and out-of-plane compression modes at quasi-static loading rates. Additional ball intrusion experiments were conducted at varying loading rates. This study compares the effects of different material systems on battery performance under standardized mechanical abuse conditions. Post-test examinations analyze surface damage and internal component fracture morphology. Two distinct fracture modes were observed: ductile fracture and brittle fracture. The findings suggest that, under the same loading mode, LTO cells exhibit distinct failure behavior compared to NMC and LFP cells, attributed to differing material properties and resulting fracture modes during intrusion. Based on the analysis of the tensile results of the battery components, the cell fracture mode may be related to the tensile strength of the separator. The loading rate significantly impacts the mechanical-electrical-thermal performance of pouch cells, resulting in increased cell stiffness and shorter internal short circuit duration at higher loading speeds. However, the effect of loading rate is consistent across cells with different material systems.

Design and mechanical performance analysis of T-BCC lattice structures

The Body-Centered Cubic (BCC) lattice structure is commonly used in high-end equipment fields, such as aerospace, due to its superior mechanical properties, lightweight characteristics, and ease of processing. However, there is a need to improve the performance-to-weight ratio of the traditional BCC lattice structure. This study utilizes topology optimization to design a T-BCC lattice structure based on the BCC unit cell, with the aim of maximizing stiffness. A model proposing the characterization of the Young's modulus of BCC lattice structures is presented. The model is based on calculations of cell porosity and beam stress analysis, assuming a large cell. This approach indirectly enables the calculation of the Young's modulus of T-BCC lattice arrays in multiple dimensions. Simulation and experimental comparison were used to analyze the compressive performance and load-bearing modes of T-BCC lattice structures, revealing the mechanisms of compressive deformation and failure modes. The accuracy of the characterization model for Young's modulus was found to be 93.1%. Compared to BCC lattice structures designed by traditional methods, T-BCC lattice structures designed via topology optimization can increase the Young's modulus by up to 36% and yield strength by 37.2%. This suggests that T-BCC lattice structures are a more lightweight and efficient solution for designing components in high-end equipment fields.

Internal waves and Rayleigh–Taylor instability in magnetized compressible strongly coupled dusty plasmas

This paper investigates the influence of compressibility on the internal wave modes and the density gradient-driven Rayleigh–Taylor (R–T) instability in magnetized strongly coupled dusty plasmas. The dusty magnetohydrodynamic model is formulated for compressible fluids, accounting for the effects of weakly coupled electrons/ions and strongly coupled dust particles under the influence of the gravitational field. The effect of the magnetic field on the dust dynamics has been incorporated through the magnetic force on the electrons and ions in quasineutral dusty plasmas. A dispersion relation of the R–T instability has been derived which has been modified because of the compressibility effect, dust acoustic wave speed and viscoelastic coefficients. The shear Alfvén and compressional viscoelastic wave modes become coupled in the dispersion characteristics. The modified R–T instability criterion is derived in terms of the Alfvén speed, viscoelastic effects and dust grain parameters. The graphical illustrations show that the growth rate of R–T instability has been suppressed due to compressibility, viscoelastic coefficients and dust acoustic speed. The results are useful to discuss the development of R–T instability in magnetized astrophysical dusty plasmas.

Shear deformation behavior of additively manufactured 316L stainless steel lattice structures

With the development of additive manufacturing, lattice structures have emerged as a disruptive technology across various fields, including aerospace, automotive, and defense. Lattice structures exhibit exceptional properties for lightweight and energy absorption capacities, especially under compressive loads. However, the lack of experimental data on complex loads, such as shear properties of lattice structures, poses challenges to their broader application across different load types. This study aims to analyze the shear deformation behavior of lattice structures and compare them with their compressive properties, enabling the safe design of lattice structures for various load applications. To achieve this, 316 L stainless steel lattice structures were fabricated using additive manufacturing in three different geometries: body-centered cubic (BCC), face-centered cubic (FCC), and octet truss (OCT), all at the same relative density. The lattice geometries were compared for their mechanical properties and deformation mechanisms under the two types of loading using DIC and FEM analyses, compression and shear tests. It was found that the mechanical properties of the lattice structures under compression and shear loads varied depending on the geometry, showing that each lattice geometry has a unique load-bearing capacity that exhibits superior mechanical properties. Furthermore, under shear loading, the struts of the BCC lattice structure showed a bending-dominated deformation mode due to the rotation of the nodes, whereas the struts of the FCC and OCT structures presented a compression and tension-dominated deformation mode. As a result, the BCC lattice specimens showed a higher shear energy absorption capacity than the other specimens and were capable of bearing higher loads. In addition, the FCC specimens showed lower shear energy absorption. The OCT specimens presented a uniform strain distribution under both compression and shear loading and showed compliant performance. The shear deformation behavior of various lattice structures has been evaluated by considering both geometrical and local strain distribution aspects. Implications for optimization guidelines and potential improvements were also discussed. These results can be used for research and development of the shear properties of lattice structures, the safe design of lattice structures, and industrial applications.

Diagnostics of Magnetohydrodynamic Modes in the Interstellar Medium through Synchrotron Polarization Statistics

One of the biggest challenges in understanding magnetohydrodynamic (MHD) turbulence is identifying the plasma mode components from observational data. Previous studies on synchrotron polarization from the interstellar medium (ISM) suggest that the dominant MHD modes can be identified via statistics of Stokes parameters, which would be crucial for studying various ISM processes such as the scattering and acceleration of cosmic rays, star formation, and dynamo. In this paper, we present a numerical study of the synchrotron polarization analysis (SPA) method through systematic investigation of the statistical properties of the Stokes parameters. We derive the theoretical basis for our method from the fundamental statistics of MHD turbulence, recognizing that the projection of the MHD modes allows us to identify the modes dominating the energy fraction from synchrotron observations. Based on the discovery, we revise the SPA method using synthetic synchrotron polarization observations obtained from 3D ideal MHD simulations with a wide range of plasma parameters and driving mechanisms, and present a modified recipe for mode identification. We propose a classification criterion based on a new SPA+ fitting procedure, which allows us to distinguish between Alfvén mode and compressible/slow mode dominated turbulence. We further propose a new method to identify fast modes by analyzing the asymmetry of the SPA+ signature and establish a new asymmetry parameter to detect the presence of fast mode turbulence. Additionally, we confirm through numerical tests that the identification of the compressible and fast modes is not affected by Faraday rotation in both the emitting plasma and the foreground.

Delamination propagation manipulation of composite laminates under low-velocity impact and residual compressive strength evaluation

The poor delamination resistance of laminated composites is always regarded as a potential threat to the service safety of the primary load-bearing structure. However, delamination is inevitable during low-velocity impact (LVI) events, as a result, the residual compressive strength of laminates is significantly reduced. Discrete interleaving is a novel strategy to enhance the damage tolerance of these composites, yet the damage mechanism of laminates modified by this method is more complicated. In this paper, we investigated the delamination failure mechanism of quasi-isotropic laminates through thermal deply experiment, and proposed a discrete interleaving scheme based on its damage characteristics. Accordingly, a series of LVI and compression-after-impact (CAI) tests were conducted to validate the design philosophy. Besides, the damage constitutive relation and evolution model applicable to discrete interleaved laminates were explored in detail, a numerical model embedded strain-rate-dependent progressive damage criterion and modified cohesive zone model was established to further study the damage mechanism. Experimental and numerical results exhibit excellent alignment. The results demonstrate that the CAI strength is enhanced by 16.48 % according to the proposed discrete interleaving method. The main reason is attributed to the employed method can manipulate the delamination propagation during the low-velocity impact loading, and then maneuver the compressive failure mode of laminates to achieve a favorable benign failure (implying higher CAI strength).

Re-evaluating the cosmological redshift: Insights into inhomogeneities and irreversible processes

Understanding the expansion of the Universe remains a profound challenge in fundamental physics. The complexity of solving general relativity equations in the presence of intricate, inhomogeneous flows has compelled cosmological models to rely on perturbation theory in a homogeneous Friedmann-Lemaître-Robertson-Walker background. This approach accounts for a redshift of light encompassing contributions from both the cosmological background expansion along the photon's trajectory and Doppler effects at emission due to peculiar motions. However, this computation of the redshift is not covariant, as it hinges on specific coordinate choices that may distort physical interpretations of the relativity of motion. In this study we show that peculiar motions, when tracing the dynamics along time-like geodesics, must contribute to the redshift of light through a local volume expansion factor, in addition to the background expansion. By employing a covariant approach to redshift calculation, we address the central question of whether the cosmological principle alone guarantees that the averaged local volume expansion factor matches the background expansion. We establish that this holds true only in scenarios characterised by a reversible evolution of the Universe, where inhomogeneous expansion and compression modes compensate for one another. In the presence of irreversible processes, such as the dissipation of large-scale compression modes through matter virialisation and associated entropy production, the averaged expansion factor becomes dominated by expansion in voids that can no longer be compensated for by compression in virialised structures. Furthermore, for a universe in which a substantial portion of its mass has undergone virialisation, adhering to the background evolution on average leads to significant violations of the second law of thermodynamics. Our approach shows that entropy production due to irreversible processes during the formation of structures plays the same role as an effective, time-dependent cosmological constant (i.e. dynamical dark energy) without the need to invoke new unknown physics. Our findings underscore the imperative need to re-evaluate the influence of inhomogeneities and irreversible processes on cosmological models, shedding new light on the intricate dynamics of our Universe.

Tuneable mechanical performance and reusability of 4D-printed heterogeneous metamaterials using shape memory biomass-derived polymer

ABSTRACT Herein, hybrid triply periodic minimal surfaces (TPMS) metamaterials were structurally designed and additively manufactured via 4D printing using a biomass-derived shape memory polymer. Two TPMS topologies including gyroid and diamond with homogeneous and graded structures were separately generated by adjusting the C parameter. The mechanical performance and deformation behaviour between the uniform and graded structures were compared, and the compressive shaping-recovery cycles were conducted. The results showed that the gyroid (C:0.7→0.4) and diamond (C:0.7→0.4) samples exhibited superior reusability to the uniform counterparts. Subsequently, heterogeneous metamaterials assembled by gyroid and diamond subsections were established and 4D-printed. It was observed that both the yielding and shape recovery were preferred occurring in the gyroid part, while the diamond subsection played a stronger supporting effect. Therefore, the compressive performance and deformation mode could be feasibly tuned by the hybridisation of TPMS, which broadened the functional and sustainable applications in energy absorption, intelligent protection and medical implants.

Stretching, Tapping, or Compressing–What Role Does Triboelectricity Play in the Signal Output from Piezoelectric Nanogenerators?

AbstractPiezoelectric energy generation is relevant for developing advanced electronics. However, the poor understanding of the influence of triboelectricity as an alternate charge generation mechanism has, in many cases, resulted in the reporting of exaggerated piezoelectric outputs. Herein, the signal output is systematically investigated from a range of organic piezoelectric materials (poled polyvinylidene fluoride (PVDF)), moderately piezoelectric (heat‐treated PVDF), and non‐piezoelectric (non‐poled PVDF), polytetrafluoroelthylene (Teflon) and nylon) under tapping and compression (33 direction) and stretching (31 direction) in both encapsulated and non‐encapsulated forms. This findings reveal that regardless of their piezoelectric properties, all tested materials exhibit substantial voltage outputs (4.2–4.6 V) during tapping, primarily attributed to the triboelectric effect at the contact interface. The triboelectric contribution to the signal is reduced by 99% in compression mode for non‐piezoelectric materials and the piezoelectric signal is the primary contributor in the stretching mode with a high signal output of 7.71 V N−1 for poled PVDF and a negligible signal (0.01–0.12 V N−1) for non‐piezoelectric materials. Moreover, elastomeric encapsulation is demonstrated to markedly increase triboelectric signals in tapping mode. These results have important implications for the future design of piezoelectric‐triboelectric devices and the accurate interpretation of the data obtained from such devices.

Fatigue lifetime predictions of notched specimens based on the critical distance and stress concentration factors

The theory of critical distances is used for evaluation of effects of notches on load-bearing capacity of notched components under static or cyclic fatigue loading. The theory can also be used to predict the fatigue life of notched components. One of the assumptions for a reliable prediction is that the critical distance is independent of the notch geometry and its stress concentration level. The study shows that the critical distance depends not only on the number of cycles to failure (under fatigue loading), but also on the notch radius. In this case, direct use of the critical distance leads to unreliable predictions. The study quantifies the relation between the model notch (from which the critical distance is determined) and the predicted notch by means of the ratio of their stress concentration factors. The predictions modified by the ratio of stress concentration factors provide results that are in satisfactory agreement with the experimental data. The predictions were made and verified on the basis of fatigue data measured on two stainless steels 1.4306 and 1.4307, and high strength structural steel S690QL. Smooth and notched specimens were tested on an ultrasonic fatigue machine in a symmetrical tension–compression mode. The results were evaluated in the regions of high cycle and very high cycle fatigue.

Investigating specimen size and shape effects on compressive mechanical behaviors of recycled aggregate concrete using discrete element mesoscale modeling

In comparison to natural aggregate concrete (NAC), recycled aggregate concrete (RAC) typically exhibits a more diverse composition of materials, heightened variability and greater inherent weaknesses. These characteristics may result in varying effects of specimen size and shape on compressive responses. Within this framework, the present study endeavors to comprehensively investigate these influences on RAC's compressive properties and their underlying mechanisms utilizing discrete element simulation technology. At the mesoscale, RAC is depicted by several components, encompassing both new and old aggregates, mortar and interfacial transition zones. Through integrating contacts for each phase, elucidating mesoscale mechanical responses with a parallel bond model and introducing Weibull random fields to delineate variations in phase properties, this study effectively simulates these mechanical responses. Subsequent extensive calculations scrutinize the repercussions of specimen size and shape on the compressive strength, elastic modulus, peak strain and failure modes of RAC across varying water-to-binder ratios. The study concludes that RAC manifests a size effect, albeit less pronounced than in NAC with an equivalent water-to-cement ratio, yet more significant than in mortar. Moreover, owing to end plate constraints, the reduction in RAC's cubic compressive strength is notably less than its prismatic compressive strength. Based on these findings, it is recommended to establish the strength size reduction coefficient and cube-to-cylinder shape coefficient for RAC at 0.86 and 0.72, respectively. Notably, these values diverge significantly from the respective 0.81 and 0.78 coefficients for NAC.

A methodological study of the hardness of cooked Chinese noodles based on the texture analyzer

Abstract A generic instrumental analysis method, matched with sensory evaluation, for the hardness test of Chinese dried noodles after cooking, was established in this study. The cut and compression mode was compared at first, followed by an analysis of the hardness response curve obtained from cut code with three-stage. Then the reliability of this method was verified with 20 commercially available noodles. Results showed that the hardness difference between the two samples obtained using compression mode was only 0.087 %. In contrast, a 6.34 % difference was obtained using cut mode with the hardness value of 296.12 ± 6.10 g and 278.47 ± 12.22 g, respectively. Three parameters, including initial hardness (F 1), material hardness (K), and final hardness (F 2), were extracted from the shear curve to characterize the hardness of cooked noodles. A ranking difference of F 1, F 2, and K between 20 commercially available noodles was found, which illustrated various characteristics of cooked noodles. In summary, the cut mode was more suitable for determining the hardness of cooked noodles; F 1, F 2, and K, obtained from a three-stage analytical method for the inner and outer hardness of cooked noodles characterization, had excellent performance to match with sensory evaluation.

Investigation on uniaxial compression and fracture damage mode of prefabricated parallel double-jointed red sandstone.

As a special type of joint fracture, the fracture evolution characteristics of parallel double joints have important engineering significance for the stability analysis of fractured rock mass. In this work, a new method for calculating stress intensity factor of parallel double-jointed fractures was importantly proposed. Physical uniaxial compression tests were carried out on parallel double jointed red sandstone filled with cement mortar under different geometric parameters, and the macroscopic mechanical properties and failure characteristics of red sandstone are deeply analyzed. The results show that the larger the connectivity rate is, the smaller the peak stress and strain are. The increase of connectivity rate will affect the change rate of transverse strain in the center of rock bridge. The closer the dip angle of the joint is, the lower the peak stress is and the shorter the failure time is. The damage mode of joint tip encroachment affects the lateral displacement of the rock bridge center, and the displacement is always close to the first damage section. The closer the joint tip is to the load, the easier the end-face penetrating cracks occur. The research content can provide basic support for guaranteeing the stability of underground engineering rock mass.

Mesoscale modeling of dynamic compressive behavior of microcapsule-based self-healing concrete under impact loading

Microcapsule-based self-healing concrete (MSC) has been widely studied, with a focus on static behavior and self-healing effectiveness. However, the dynamic mechanical properties of MSC have rarely been studied. This study presents a mesoscale numerical investigation of the dynamic compressive behavior of MSC under impact loading. In mesoscale, MSC is regarded as a four-phase composite material mainly composed of coarse aggregates, interface transition zones, cement mortar, and microcapsules. A pseudo 3D numerical model is constructed by combining a slice of a detailed mesoscale model with a homogenous 3D model. The mesoscale MSC slice models with different mass fractions of microcapsules (0%, 2%, 5%, and 8%) are constructed. Different coarse aggregate shapes (i.e., circles, ellipses, and polygons) are considered. The uniaxial dynamic compressive behaviors of MSC materials under loads of different strain rates are numerically simulated and compared with those from split Hopkinson pressure bar tests previously done by the authors. The comparison results show that the present mesoscale model can accurately predict the compressive strength and failure mode of MSC. The effects of the microcapsules ratio and strain rate on the dynamic strength are studied. Results show that the MSC compressive strength decreases with the increase in microcapsules and increases with the increase in strain rate. The dynamic increase factor (DIF) of the specimen is jointly contributed by the material DIF, inertial constraints, and heterogeneity. Different aggregate shapes have little effect on the simulation results of MSC behavior. The obtained dynamic mechanical properties of MSC may assist in designing MSC to resist collisions or explosions.