Dynamic Compressive Properties Research Articles

Influence of waste glass and rice husk ash on the dynamic compressive properties and variable-angle shear characteristics of concrete after high-temperature treatment: Experimental and numerical study

This study investigates the use of glass sand, glass powder, and rice husk ash in concrete to mitigate the depletion of natural river sand and cement resources. High-temperature environments were simulated using a muffle furnace, and dynamic compression and variable-angle shear tests were conducted to assess the effects of these recycled materials on the mechanical properties of concrete under normal and high-temperature conditions. Results show that while the dynamic compressive strength of ordinary concrete decreases with increasing temperature, the addition of waste glass and rice husk ash enhances strength and modifies the temperature-strength relationship. Rice husk ash increases the strain rate sensitivity, resulting in higher stress rates and more gradual stress-strain curves. Glass sand concrete exhibited improved energy absorption and resistance to dynamic loads, especially with rice husk ash at elevated temperatures. Additionally, concrete containing glass demonstrated superior cohesion and internal friction angles. An improved plastic damage model was validated through simulations, showing enhanced damage resistance in concrete with rice husk ash at temperatures below 400 °C. This study highlights the potential of waste glass and rice husk ash in improving concrete performance and damage resistance.

Study on mechanical behaviour and microstructure evolution of wire-arc directed energy deposition Co-free maraging steel under dynamic compression

ABSTRACT The dynamic compression property of maraging steel is an important basis for determining the impact resistance of the structure, and the related studies are few. To enrich the relevant data and elucidate the relevant mechanisms, in this work, a new Co-free maraging steel component is fabricated by wire-arc direct energy deposition (DED), and the quasi-static tensile properties and dynamic compression properties are tested. The results show that the deposition direction exhibits the highest quasi-static tensile properties. Strain rate strengthening effect, grain refinement and grain boundary strengthening are the main strengthening mechanisms during dynamic compression. With the increase of strain rate, dynamic recrystallization intensifies, causing the grain size and dislocation density to decrease. Under dynamic condition, strain-induced martensite phase transformation reduces the austenite content; temperature rise and dynamic recrystallization limit the degree of martensite phase transformation. Strain rate sensitivity of the strength is independent of the direction.

Effects of recycled sand and shell sand as sand replacement on the dynamic properties of seawater sea-sand recycled aggregate concrete

This study utilizes recycled sand and shell sand to replace sea-sand in seawater sea-sand recycled aggregate concrete (SSRAC) and explores their dynamic compressive properties. A total of 28 sets of specimens were designed, and their stress-strain curves under different strain rates were analyzed. The findings indicated that the dynamic increasing factor (DIF) of peak stress in SSRAC reached its peak at a 50% replacement ratio of recycled sand, exhibiting a 3.9% to 7.7% increase compared to a 0% replacement ratio. Conversely, there was an overall decreasing trend in the DIF when the replacement ratio of shell sand increased. Using recycled sand resulted in an average reduction of approximately 45% in the elastic modulus of the interfacial transition zone (ITZ), while the introduction of shell sand slightly increased that of it. Finally, considering strain rate effects, a dynamic compressive prediction model for SSRAC with different types of fine aggregates was established.

Laser powder bed fusion of Fex(CoCrMnNi)100-x medium-entropy ferrous alloys: Processability, microstructure and dynamic deformation mechanism

In this work, Fex(CoCrMnNi)100-x (x = 40, 60 and 80 at.%) medium-entropy ferrous alloys (MEFAs) were fabricated through laser powder bed fusion (LPBF) of mixed powders composed of FeCoCrNiMn and Fe powders, and the dynamic compressive properties and deformation mechanisms were studied with combination of experiment and molecular dynamics simulation. The results demonstrate that all MEFAs exhibit good processability.The Fe40 and Fe60 samples were predominantly composed of FCC phase with coarse grains, while the Fe80 mainly consisted of BCC phase with a smaller grain size. When subjected to quasi-static and dynamic compression at 3000/s, the yield strengths of Fe40, Fe60 and Fe80 increases by 131, 220 and 256 MPa, respectively, illustrating the positive strain rate sensitivity and influence of Fe on the mechanical properties of MEFAs. Further, both the single-crystal and the polycrystalline models suggested that the incompatibility between the BCC and FCC phases is responsible for the enhancement of strength. Therefore, it is more likely to produce deformation twins, dislocations and thus stress concentration around the BCC phase, which is consistent with the TEM observations.

Dynamic compressive behavior of hybrid basalt-polypropylene fibers reinforced coral aggregate concrete

In this study, the effects of strain rate, fiber type, and hybrid fiber content on the dynamic mechanical properties of basalt-polypropylene fiber reinforced coral aggregate concrete (HBPRCAC) under impact loading are investigated using a split-Hopkinson pressure bar (SHPB) with a 75 mm diameter. The results demonstrated that the incorporation of basalt fiber (BF) and polypropylene fiber (PF), particularly when mixed, effectively reduced the failure of HBPRCAC. With an increase in strain rate, the failure of HBPRCAC exhibited a more severe pattern; even at low strain rates, cracks directly passed through the coral aggregate, causing damage. The failure modes of BF and PF were related to the strain rate. The probability of BF and PF being pulled out was higher at low strain rates than at high strain rates, where BF and PF predominantly exhibited snap failures. Additionally, the dynamic increase factor (DIF) of the dynamic compressive strength and dynamic modulus of elasticity for HBPRCAC demonstrated a decimal logarithmic linear increase with strain rate, while the dynamic critical strain and impact toughness of HBPRCAC exhibited a linear increase with strain rate. The mixed addition of BF and PF had varying effects on the strain rate sensitivity of HBPRCAC's dynamic mechanical properties, but the fiber mixing content was significantly positively correlated with the strain rate effects on the dynamic compressive mechanical properties of HBPRCAC. The dynamic compressive strengths of BPCAC-0.1 and BPCAC-0.2 at strain rates of 128–135 s−1 were increased by 78.66 % and 88.47 %, respectively, compared to those at strain rates of 33–36 s−1. The dynamic moduli of elasticity for BPCAC-0.1 and BPCAC-0.2 showed increases of 16.47 % and 13.06 %, respectively, compared to that of coral aggregate concrete. Moreover, the critical strain and impact toughness of BPCAC-0.2 were the highest at all tested strain rates.

Evaluation of quasi-static and dynamic compressive properties of Ti-6Al-4 V functionally graded shell lattices with minimal surfaces

Functionally graded shell (FGS) lattices have recently captivated enormous research interest in engineering applications for their outstanding mechanical and energy-absorbing performances. This paper designs FGS lattices featuring I-WP triply periodic minimal surfaces using implicit functions. FGS and uniform shell (US) samples made of Ti-6Al-4 V powder are manufactured utilizing laser powder bed fusion technology. Quasi-static compression and drop-weight impact experiments are conducted to evaluate the mechanical and energy-absorbing performances as well as deformation mechanism of FGS and US samples. The results demonstrate that the deformation modes of the samples under both loading conditions are similar, which is basically attributed to the drop-weight impact velocities being lower than the critical speeds calculated by the rigid-power-law hardening (RPLH) model. Additionally, the effects of loading velocity on the deformation mechanisms of US and FGS lattices are simulated, and homogenization, transition, and shock deformation models are predicted by the RPLH model. The FGS sample exhibits distinct layer-by-layer failures and eliminates the abrupt shear band under dynamic and quasi-static loadings. Compared to the quasi-static results, a notable strain rate hardening effect is observed under the dynamic condition, mainly due to the hardening of the row material. Consequently, the elastic modulus, yield strength, compression strength, and cumulative energy absorption of the US sample under drop-weight impact loading improved by 18.74 %, 56.52 %, 45.31 %, and 6.62 %, respectively. However, the FGS sample shows less sensitivity to strain rate owing to the layer-by-layer deformation mechanism, and their elastic modulus, yield strength, compression strength, and cumulative energy absorption only increased by 11.84 %, 34.72 %, 36.85 %, and 3.86 %, respectively. The FGS lattices exhibit a low peak stress during the compression process, which is favorable for industrial applications in crashworthiness and energy absorption.

Effects of ZrO2 ceramics doped with varying content on the mechanical properties and energy release characteristics of W-Zr alloys

A W-Zr alloy doped with ceramic powder W54.5Zr35-xNi6.7Fe3.3Mo0.5 (ZrO2) x was prepared by powder metallurgy. The effects of the ceramic content on the dynamic and static compressive mechanical behavior and energy release properties of the alloy were studied. The results showed that the addition of ceramics enhanced the energy release characteristics of the W-Zr alloy, and made the alloy break more thoroughly and the fragment cloud distribute evenly. The reaction delay time was shorter and the energy release reaction was more complete. However, the maximum temperature of the alloy reaction decreased. In addition, the addition of ceramics improves the mechanical properties of the material, and its compressive strength is much higher than that of traditional W-Zr alloys.(ZrO2)1 exhibited good mechanical behavior and energy release characteristics. The aftereffect damage performance was further verified using a ballistic gun experiment. Ballistic gun test results showed that (ZrO2) 1 can penetrate A92124 aluminum targets with a thickness of 2 mm at a speed of 809.3 m s−1 and ignite post-target absorbent cotton, with both penetration and post-target damage capabilities.

Oblique penetration of spherical tungsten alloy projectiles on high-strength steel plates

The uniaxial tensile and dynamic compression properties of 22SiMn2TiB high-strength steel were first investigated, which shows certain strain-rate effects and obvious temperature-softening effects. Ballistic tests were carried out on 12 mm thick 22SiMn2TiB steel using ∅11 mm tungsten projectiles at 0°∼45° obliquity and a velocity of 500∼900 m/s. The study found that the ballistic limit velocity (BLV) increased monotonously with the increase of the obliquity. Based on the De Marre equation, a BLV calculation model was calibrated, which predicted experimental results well. Corresponding numerical simulation was carried out using LS-DYNA with fitted Johnson-Cook model parameters, its results are in good agreement with the test's. Additionally, the protective mechanism of the 22SiMn2TiB steel plate at an oblique angle was revealed through microscopic morphology analysis of the high-strength steel plate. It identifies adiabatic and normal shear failure, tensile and tensile-shear mixed failure, and the formation of different cracks in two groups, ultimately leading to plugging failure. The study provides a reference for the engineering design of the defensive structures using 22SiMn2TiB high-strength steel.

High-temperature dynamic failure behavior and compressive mechanical properties of alumina porous ceramic with various pore sizes

The dynamic compressive mechanical properties of alumina porous ceramic with various average pore sizes are tested at strain rates and temperatures ranging from 0.01 s−1 to 2900 s−1 and 20 °C to 850 °C, respectively. The corresponding 3d Voronoi models are employed to simulate the meso‑characteristics of cells and failure characteristics of alumina porous ceramic in multiscale. The failure in macroscale of quasi-static compression is fragmentation, and that of dynamic compression is comminution. But in mesoscale, the failure, both of quasi-static and dynamic compression, is the fracture of cell walls. Its dynamic strength increases with the increase of strain rate, but decreases with the increase of temperature and average pore size. The increase in temperature and average pore size leads to a decrease in its strain rate sensitivity. Its Young's modulus is not sensitive to the strain rate, but increases with the decrease of average pore size, and decrease with the increase of temperature, which is presented as a temperature and average pore size dependent function. The strain rate and temperature effects are also presented by average pore size dependent functions, respectively. A constitutive model is proposed based on them. It shows that the constitutive model fits well with the experimental results.

Experimental method for investigating the dynamic compression behaviour of fibre-reinforced polyurethane shoe press belts under press nip conditions

An experimental method was developed to examine the dynamic compression properties of structured polyurethane composites used as press belts within a shoe press of a paper machine. The objective was to investigate the influences of the geometrical surface structure and the matrix material composition on the compression properties. Two polyurethane formulations were tested under varying specimen conditions. The results show that the dynamic compression modulus increases with the applied load rate and that temperature and water saturation reduce the influence of dynamic effects on the compression modulus. Furthermore, it was observed that modifications of the matrix material have a more significant impact on the dynamic compression modulus than adaptions in the geometrical structure. This is addressed to the relatively small variations in possible surface designs. Finally, a rate-sensitivity index is introduced to quantify the tested specimens’ rate-sensitive behaviour.

Synergistic effect of microfibers and oriented steel fibers on mechanical properties of UHPC

The study introduces a novel approach to enhance the properties of Ultra-High Performance Concrete (UHPC) through multi-scale synergistic reinforcement using microfibers (0.66 mm) and oriented steel fibers (13 mm). Various aspects were investigated, including rheological properties, fiber orientation, and fiber pull-out characteristics. Besides, quasi-static mechanical properties and dynamic compressive properties of UHPC were tested and the bending failure was monitored by acoustic emission technique. Experimental results showed that microfiber improved mechanical properties of UHPC matrix and enhanced the fiber-matrix interface. Compressive strength, flexural strength, and toughness of specimens were increased by as high as 25 %, 78 %, and 55 %, respectively, when microfiber was mixed with oriented steel fibers. In terms of dynamic impact performance, UHPC exhibited significant strain rate sensitivity, and microfibers blended with oriented steel fibers resulted in complete damage pattern when subjected to impact loading, and dynamic compressive strength and energy absorption increased by 48.5 % and 54.8 %, respectively. Therefore, oriented steel fibers coupled with microfibers provide an effective method to enhance the mechanical performance of UHPC.

Polymer/Carbon Fiber Co-modification: Dynamic Compressive Mechanical Properties of Carbon Fiber Modified Polymer Reinforced Concrete

Polymer/Carbon Fiber Co-modification: Dynamic Compressive Mechanical Properties of Carbon Fiber Modified Polymer Reinforced Concrete

Dynamic compressive behavior of steel fiber synergistically reinforced cellular concrete under high strain-rate loading

To better understand the reinforcement and toughness effects of steel fibers, a 75-mm split Hopkinson pressure bar (SHPB) device was used to test the uniaxial dynamic compression properties of steel fiber synergistically reinforced cellular concrete (SFSRCC) under high strain rates. The dynamic compression performance characteristics of the SFSRCC, including the stressstrain curve, dynamic strength, impact toughness and failure mode, were analyzed. The results showed that the dynamic strength, peak strain and impact toughness of SFSRCC increase with increasing strain rate. Compared with that of cellular concrete (SAP10S0), a higher steel fiber volume ratio corresponded to a greater enhancement in the dynamic performance characteristic indices of the SFRCC. The maximum increases were 138.4%, 180.0% and 280.0% for the DIF, peak strain, and impact toughness, respectively. The damage degree of the SFSRCC specimen decreased with increasing fiber content, and a larger area of residual "core retention" was observed, which indicated that the impact resistance of the SFSRCC with a high fiber content was improved. An empirical formula that can accurately characterize the dynamic strength increase factor (DIF) of SFSRCC with high strain rates was proposed, and the prediction results obtained by using the DIF of the SFSRCC were highly consistent with the test results, which confirmed its effectiveness. To further quantify the strain rate enhancement effect and fiber content for the reinforcement and toughening ability of SFSRCC, the relationships between the peak strength/peak strain/impact toughness and strain rate and between the DIF increment ratio/strain energy density increment ratio and fiber volume fraction were determined. In conclusion, the dynamic compression performance characteristics of SFSRCC can be enhanced by incorporating an appropriate quantity of steel fibers with a dynamic impact load.

Dynamic compressive properties of UHPC under one-dimensional stress wave: The influence of steel fiber morphology and curing regime

The low matrix strength and insufficient toughness of conventional concrete structures seriously threaten the service performance when subjected to intensive compressive waves. This study aims to comprehensively investigate the impact of steel fiber morphology and curing regime on the dynamic compressive properties of Ultra-high performance concrete (UHPC) under one-dimensional stress wave. Seeking to improve its impact resistance without changing the mix ratio. Three steel fiber types (straight, wave, hooked) and two curing regimes (steam at 90 °C, dry heat at 180 °C) were selected as experimental variables. Quasi-static mechanical properties of UHPC were initially calibrated, followed by dynamic compressive tests utilizing the Split Hopkinson Pressure Bar (SHPB) system. The compressive stress-strain relationships and corresponding dynamic mechanical parameters of six types of UHPC were calculated under five impact velocities (8.5 m/s, 10.8 m/s, 13.1 m/s, 15.2 m/s, 17.3 m/s). Furthermore, the dynamic failure mode and evolutionary process of UHPC under high-speed impact was meticulously captured by a high-speed camera. CT scanning was utilized to observe the crack propagation path and damage patterns under low strain rate. Finally, SEM and EDS testing was conducted to unravel the underlying mechanisms of the curing regime and fiber morphology on the dynamic compressive properties of UHPC. The recalibrated empirical DIFfc model suitable for UHPC under strain rates of 37 s-1 to 212 s-1 was proposed.

Incorporation of Disposed Face Mask to Cement Mortar Material: An Insight into the Dynamic Mechanical Properties

Incorporating masks into building materials offers a potential solution to the environmental threat of disposable masks with promising material performance. However, research on their dynamic properties is lacking to further determine the application range of the new composite. This study addresses this gap by shredding face masks into strips and incorporating them into mortars at varying volume ratios. The integrity and compactness of the mortar was measured and characterized by P-wave velocity, while dynamic compression properties were explored using a split Hopkinson pressure bar (SHPB) system. Subsequently, sieve analysis was conducted on the fractured specimens. The results indicate that incorporating masks generally improves the mortar integrity and the fragmentation after impacting. The dynamic uniaxial compression strength (DUCS) decreased for all mixing designs compared to plain ones under a constant loading rate. Meanwhile, the dissipated energy density showed a similar trend to the P-wave velocity, exhibiting less pronounced enhancement at higher loading rates. According to the dynamic characteristics, a dynamic constitutive model based on the Lemaitre principle and Weibull distribution of damage is developed and validated. The test results are further understood through the perspective of the mechanism of mask inclusion.

Investigation of dynamic compression properties of lightweight engineered geopolymer composites containing different ceramsites (LW-EGC)

Lightweight engineering geopolymer composites (LW-EGC) can contribute to green building materials products by taking advantage of the advantages of man-made ceramsite and geopolymers. In this paper, an active "sacrifice" method was proposed, which is based on the idea that low elastic modulus ceramsites are preferentially damaged or ruptured during the impact loading process, thus absorbing and dissipating the impact energy. LW-EGC was enhanced by PVA fiber with volume fraction of 2% and multi-walled carbon nanotubes with mass fraction of 0.15%. The dynamic compression properties of LW-EGC containing different ceramsites were studied by using Φ100 mm split Hopkinson pressure bar (SHPB) test device. The compression characteristics of the LW-EGC under an impact load were evaluated, including the strain rate, dynamic stress–strain relationship, elastic modulus, dynamic increase factor (DIF), energy absorption, and failure patterns. The results showed that the dynamic peak stress, dynamic peak strain, DIF, energy absorption and damage degree of LW-EGC all increased with the increase of strain rate, showing obvious strain-rate sensitivity. At high strain rate, the dynamic elastic modulus mainly showed softening effect. At the same strain rate, the impact resistance of LW-EGC-1 containing fly ash ceramsite was the best, and the damage degree of LW-EGC-3 containing shale ceramsite was the lowest. Empirical DIF formulas of the LW-EGC was proposed; the DIF increased approximately linearly with the strain rate in a logarithmic manner.

Dynamic compressive properties of 2D-aligned steel fiber reinforced cement-based composites

Dynamic compression may happen in some protective cement-based composite structures. Cement-based composites are compressed at loading direction when subjected to dynamic compression, however expansion occurs in the direction perpendicular to the loading. As a quasi-brittle material, the expansion of the cement-based composites may result in the disintegration and hence the failure of the material. Incorporating steel fibers is a valid solution of reinforce the composites to resist dynamic compression. Usually, steel fibers are randomly dispersed throughout the composites. Actually, steel fibers with the same direction of the dynamic loading are ineffective. Only steel fibers perpendicular to the orientation of the dynamic compression load can they effectively restrict the expansion of the composites and enhance its dynamic compressive properties. So, cylindrical specimens using two-dimensionally aligned steel fiber reinforced cement-based composites (2D-SFRC) were prepared and tested. In specimens all steel fibers are perpendicular to the dynamic compression load, which limits the circumferential expansion and deformation of the specimens when subjected to dynamic compression and significantly enhances its performance resisting dynamic compression. When preparing 2D-SFRC specimens, the magnetic field was used to align steel fibers to achieve the two-dimensionally aligned steel fiber in specimens. Then, 2D-SFRC specimens were tested for their dynamic compressive properties. The results indicate that the dynamic compressive strength and toughness of 2D-SFRC specimens are significantly increased compared with unidirectional and random steel fiber distribution specimens. By analyzing the stress distribution and tensile force of steel fibers, the reinforcing mechanism of two-dimensionally aligned steel fibers was revealed. The two-dimensional alignment of steel fibers increased the number and the tensile force of fibers, which effectively restrained the circumferential expansion of the cylinder specimens.

Dynamic Compressive Mechanical Properties of Rock-like Material with Bedding Planes Subject to Different Impact Loads

Dynamic Compressive Mechanical Properties of Rock-like Material with Bedding Planes Subject to Different Impact Loads

Dynamic compressive property of extruded VW75-Ti (wt.%) alloy under high strain rates

The dynamic compressive properties of extruded VW75 and VW75+Ti alloys were investigated by using a split Hopkinson pressure bar (SHPB) at 25°C under high strain rates of 1, 600-2, 700 s-1 in the present work, and the microstructure evolution after deformation was inspected by OM, SEM, and EBSD. The results demonstrated that the maximum stress value rises with the escalating strain rate in the course of impact, and the true stress-true strain curves of the two alloys exhibit strain strengthening and positive strain effect. The addition of Ti particles refines alloy grains, increases fracture strength, and decreases the twinning ratio.

Dynamic compressive properties and self-similarity characteristics of deep coral reef limestone subjected to high loading rates

Coral reef limestone is a kind of porous anisotropic geo-material. Understanding its dynamic mechanical properties subjected to high loading rates is of great significance to the blasting excavation and military attack defense of the reef underground space. In this paper, the Split Hopkinson Pressure Bar tests were carried out on the specimens of deep coral reef limestone in the South China Sea, and the difference of dynamic response between deep reef limestone and shallow calcified coral skeleton was revealed. The results show that the pore structure affects the dynamic deformation response of coral reef limestone, which makes the strain rate of the specimen independent of other mechanical parameters. However, the high loading rate overcomes the influence of the primary pore structure on the strength, so that the dynamic compressive strength and the degree of breakage are linearly related to the stress rate. In addition, under high loading rate, the coral framework limestone is mainly damaged by tension, which is significantly different from the calcified coral skeleton along the coral growth line. At the same strain rate, the fractal dimension of the dry specimen is greater than that of the saturated one, and the self-similarity characteristics of the specimen fragments that reach the crushing level at higher strain rate are poor. The viscous effect of water hinders the propagation of cracks in the coral framework limestone, but free water reduces the surface energy of the crystal boundary. These two kinds of mechanisms compete with each other, and the key factors controlling the competition mechanism are water content and loading rate.