Accumulation Of Elastic Energy Research Articles

Effect of Sandstone Pore Morphology on Mechanics, Acoustic Emission, and Energy Evolution

Roadway section form is an important part of the underground engineering structure, and it directly affects the overall stability of the roadway and the occurrence of underground disasters in coal mines. Based on this, this paper adopts a TYJ-500 electro-hydraulic servo rock shear rheology testing machine to conduct a uniaxial compression test on sandstone containing different prefabricated hole section morphology and analyzes the damage characteristics seen during the damage evolution process, with the help of a high-speed camera and acoustic emission monitoring equipment. The test results show that the pore morphology is the main factor affecting the mechanical parameters of sandstone, and the peak stress and elastic modulus of sandstone with pore sections have the characteristics of increasing and decreasing at the same time, except for the intact rock samples. The pore morphology exhibits central symmetry (circular holes and rectangular holes) damage, more pressure-shear cracks and shear cracks, and the acoustic emission characteristics of high-energy–low-amplitude–low-count of the “two low-trend and one high-trend characteristic curves” attributes; moreover, due to the special existence of its pore morphology, it leads to the rock samples having less energy accumulation and release. The axisymmetric hole types (trapezoidal holes and straight-wall domed holes) are damaged by tensile cracks and shear cracks, and their acoustic emission characteristics show the characteristic properties of “three high-trend characteristic curves” of high-energy–high-amplitude–high-count, and there is a strong elastic energy accumulation and output. The conclusions of this article can provide a certain theoretical basis for the design of coal mine roadway sections in underground structures, failure analysis, and stability evaluation of roadway structures.

A rapid-response soft end effector inspired by the hummingbird beak.

Biology is a wellspring of inspiration in engineering design. This paper delves into the application of elastic instabilities-commonly used in biological systems to facilitate swift movement-as a power-amplification mechanism for soft robots. Specifically, inspired by the nonlinear mechanics of the hummingbird beak-and shedding further light on it-we design, build and test a novel, rapid-response, soft end effector. The hummingbird beak embodies the capacity for swift movement, achieving closure in less than [Formula: see text]. Previous work demonstrated that rapid movement is achieved through snap-through deformations, induced by muscular actuation of the beak's root. Using nonlinear finite element simulations coupled with continuation algorithms, we unveil a representative portion of the equilibrium manifold of the beak-inspired structure. The exploration involves the application of a sequence of rotations as exerted by the hummingbird muscles. Specific emphasis is placed on pinpointing and tailoring the position along the manifold of the saddle-node bifurcation at which the onset of elastic instability triggers dynamic snap-through. We show the critical importance of the intermediate rotation input in the sequence, as it results in the accumulation of elastic energy that is then explosively released as kinetic energy upon snap-through. Informed by our numerical studies, we conduct experimental testing on a prototype end effector fabricated using a compliant material (thermoplastic polyurethane). The experimental results support the trends observed in the numerical simulations and demonstrate the effectiveness of the bio-inspired design. Specifically, we measure the energy transferred by the soft end effector to a pendulum, varying the input levels in the sequence of prescribed rotations. Additionally, we demonstrate a potential robotic application in scenarios demanding explosive action. From a mechanics perspective, our work sheds light on how pre-stress fields can enable swift movement in soft robotic systems with the potential to facilitate high input-to-output energy efficiency.

Regularities of Martensitic Transformations in New Medium-Entropy Single Crystals of CoNiAlFe Alloys

This paper deals with the martensitic transformation and functional properties in the quenched single crystals of the Co35Ni35Al28Fe2 medium-entropy alloy, oriented along the [001]B2-direction. The microstructure and chemical composition of the single crystals have been studied in detail using transmission and scanning electron microscopy. The {111}L10 martensite twins up to 10-20 nm width and γ/γ′-phase precipitations larger than 100 μm are detected. The thermoelastic B2-L10 martensitic transformation upon stress-free cooling/heating in single crystals of Co35Ni35Al28Fe2 alloy is characterized by the accumulation of elastic energy, which is the driving force of the reverse martensitic transformation, and the low dissipation energy. The reverse transformation starts at lower temperatures than the forward transformation Ms>As. The regularities of the stress-induced B2-L10 martensitic transformation change due to an increase in the contribution of the dissipated energy and Msσ<Asσ. There is shape memory effect with the reversible strain (3.2±0.3)% and high temperature superelasticity with the reversible strain (3.3±0.3)% in the temperature range from 323 K to ≥548 K in the [001]B2-oriented single crystals. These crystals withstand stress up to 1200 MPa in compression without destruction.

Role of viscoelasticity in the appearance of low-Reynolds turbulence: considerations for modelling.

Inertial effects caused by perturbations of dynamical equilibrium during the flow of soft matter constitute a hallmark of turbulence. Such perturbations are attributable to an imbalance between energy storage and energy dissipation. During the flow of Newtonian fluids, kinetic energy can be both stored and dissipated, while the flow of viscoelastic soft matter systems, such as polymer fluids, induces the accumulation of both kinetic and elastic energies. The accumulation of elastic energy causes local stiffening of stretched polymer chains, which can destabilise the flow. Migrating multicellular systems are hugely complex and are capable of self-regulating their viscoelasticity and mechanical stress generation, as well as controlling their energy storage and energy dissipation. Since the flow perturbation of viscoelastic systems is caused by the inhomogeneous accumulation of elastic energy, rather than of kinetic energy, turbulence can occur at low Reynolds numbers.This theoretical review is focused on clarifying the role of viscoelasticity in the appearance of low-Reynolds turbulence. Three types of system are considered and compared: (1) high-Reynolds turbulent flow of Newtonian fluids, (2) low and moderate-Reynolds flow of polymer solutions, and (3) migration of epithelial collectives, discussed in terms of two model systems. The models considered involve the fusion of two epithelial aggregates, and the free expansion of epithelial monolayers on a substrate matrix.

Research on rockburst prevention systems based on the attenuation law of coal and rock vibration wave energy

During the coal and rock mass fracture process, elastic properties are released and vibration waves are radiated outward. The energy attenuation characteristics of these waves can describe the cumulative damage and elastic energy accumulation of the mass. To investigate coal and rock mass failure characteristics and energy attenuation rules during rockburst, numerical simulation and laboratory testing were utilized to study the energy transfer laws under various parameters. Six variables, including elastic modulus, Poisson’s ratio, bulk density, cohesion, internal friction angle, and void ratio, were selected to simulate the rockburst energy release process under different parameter combinations by adding surface pressure to the model. The coal and rock mass energy attenuation coefficient was obtained by fitting the node energy straight line using the least squares method. The six variables’ influence on vibration wave energy transfer was obtained using analytic hierarchy process program written in MATLAB, and a comprehensive calculation formula was proposed. Using the energy attenuation coefficient, the rock layer energy diffusion distance was calculated and compared with the roof collapse rock layer step distance, resulting in the roof rock layer cutting distance determination. By roof rock strata precutting, rockburst occurrence can be prevented, ensuring safe and efficient coal mine production.

Decomposing significant factors of Coulomb stress and its components in injection-induced seismicity

Injection-induced seismicity has been a focus of industry for decades as it poses great challenges to the associated risk mitigation and hazard assessment. The response surface methodology is integrated into the geo-mechanical model to analyze the effects of multiple factors on induced seismicity during the post shut-in period. We investigate the roles of poroelastic stress and pore pressure diffusion and examine the differences in the controlling mechanism between fault damage zones and the fault core. A sensitivity analysis is conducted to rank the selected factors, followed by a Box‒Behnken design to form response surfaces and formulate prediction models for the Coulomb stress and its components. Reservoir properties significantly affect the potentials of induced seismicity in the fault by changing pore pressure diffusion, which can be influenced by other factors to varying degrees. Coulomb stress is greater in pressurized damage zones than in fault cores, and the seismicity rate exhibits a consistent variation. Poroelastic stress plays a similar role to pore pressure diffusion in the stability of the fault within the pressurized damage zones. However, pore pressure diffusion dominates in the fault core due to the low rigidity, which limits the accumulation of elastic energy caused by poroelastic coupling. The slip along the fault core is a critical issue to consider. The potential for induced seismicity is reduced in the right damage zones as the pore pressure diffusion is blocked by the low-permeability fault core. However, poroelastic stressing still occurs, and in deep basements, the poroelastic effect is dominant even without a direct increase in pore pressure. The findings in this study reveal the fundamental mechanisms behind injection-induced seismicity and provide guidance for optimizing injection schemes in specific situations.

Experimental study on the significance of pressure relief effect and crack extension law under uniaxial compression of rock-like materials containing drill holes

The drilling pressure relief technology is an effective way to reduce the accumulation of elastic energy in the tunnel envelope, which can reduce the risk of regional ground pressure occurrence. However, there is a lack of theoretical guidance on which drilling parameter has the greatest degree of influence on the effectiveness of pressure relief. The uniaxial compression tests were conducted to study the relationships between drilling parameters (the diameter, depth, and spacing) and the mechanical properties and deformation modulus of specimens. The results show that: (1) The drilling diameter (DDR) and drilling depth (DDH) of single-hole specimens negatively correlate with the peak-failure strength and deformation modulus, while the drilling spacing (DS) of double-hole specimens positively correlates with the peak-failure strength and deformation modulus. It shows that the borehole diameter has a more significant effect on the decompression effect. (2) With the help of the Grey Relational Analysis, the factors affecting the peak-failure strength and deformation modulus of the drilled specimens were ranked in significance. From the largest to the smallest, they are DDR, followed by DDH and DS. (3) The role of the pressure relief mechanism is to transfer the high stress in the shallow part of the roadway to the deep part, reduce the peak strength of destruction and deformation modulus of the peripheral rock in the drilled section, so that the characteristics of the mechanical behavior of the rock are significantly weakened, and the range of the area of the drilled hole decompression is enlarged. During the loading of the borehole, the borehole stress field dominates in the early stage, and cracking starts near the borehole along the direction perpendicular to the direction of maximum principal stress (horizontal direction). In the later stage, the maximum principal stress field dominates and vertical cracks with large widths appear. During crack expansion, the plastic energy dissipation effect is enhanced and the deep impact conduction path is weakened, thus protecting the roadway. This study determined the significance of the pressure relief effect of different drilling parameters, which can guide reasonable modifications of drilling parameters in the field.

Fractional Criticality Theory and Its Application in Seismology

To understand how the temporal non-locality («memory») properties of a process affect its critical regimes, the power-law compound and time-fractional Poisson process is presented as a universal hereditary model of criticality. Seismicity is considered as an application of the theory of criticality. On the basis of the proposed hereditarian criticality model, the critical regimes of seismicity are investigated. It is shown that the seismic process has the property of «memory» (non-locality over time) and statistical time-dependence of events. With a decrease in the fractional exponent of the Poisson process, the relaxation slows down, which can be associated with the hardening of the medium and the accumulation of elastic energy. Delayed relaxation is accompanied by an abnormal increase in fluctuations, which is caused by the non-local correlations of random events over time. According to the found criticality indices, the seismic process is in subcritical regimes for the zero and first moments and in supercritical regimes for the second statistical moment of events’ reoccurrence frequencies distribution. The supercritical regimes indicate the instability of the deformation changes that can go into a non-stationary regime of a seismic process.

Influence of coupling mechanism of loose layer and fault on multi-physical fields in mining areas

Coal mining under the geological conditions of a loose layer will lead to the intensification of surface movement and deformation, and mining under the geological conditions of a fault will lead to the living slip of a fault. Mining under both conditions will have a great impact on the safety of coal production. To reveal the evolution law of the coupling mechanism of loose layer and fault on the multi-physical fields of overburden, the numerical simulation method is used to simulate the coupling of loose layer and fault with different thicknesses, analyze the changes of vertical stress on the key strata, the changes of surface subsidence, the evolution of elastic energy on the fault zone and the changes of activated slip area of the fault zone. The simulation analysis shows that the vertical stress change trend of the key strata gradually changes from the "V" shape to the "W" shape at the beginning of mining, and the vertical stress concentration will occur at the fault. The loose layer will promote surface subsidence, and the fault will hinder the surface subsidence to a certain extent. The loose layer and the fault alternately affect the surface subsidence. The elastic energy accumulation on the key strata is mainly concentrated on both sides of the goaf. The elastic energy in the center of the goaf is dissipated. The elastic energy accumulation in the fault zone starts from the shallowly buried fault and gradually develops to the deeply buried fault. The instability of fault activation has gone through the initial stage of activation—the intensification stage of activation—the stable stage of activation. Under the working conditions of no loose layer, thin loose layer, and thick loose layer, the fault zone is the first to undergo living slip, and under the action of an extra-thick loose layer, there is a certain lag in the activation slip of the fault zone.

Evaluation of energy accumulation, strain burst potential and stability of rock mass during underground extraction of a highly stressed coal seam under massive strata-a field study

Severe geotechnical problems like strain burst, side spalling, roof fall, irregular caving, the premature collapse of rib/remnant pillars, etc. are frequently observed during the mining of highly stressed coal seams under massive overlying strata. In this study, different underground structures and adequate support systems under such complex geological conditions are designed by evaluating energy accumulation, strain burst potential, stress conditions and stability of the rock mass. An energy-based safety factor is derived and implemented through numerical modelling to identify the yield zones in the surrounding rock mass. The strain burst potential in different locations is also evaluated by the elastic energy accumulation and the Burst Potential Index (BPI) whose maximum values reach 628 kJ/m3 and 47.6% respectively during depillaring operations. These values indicate the significant strain burst and side spalling conditions which are corroborated by the field investigations and monitoring data by geotechnical instruments. Control measures have been taken by leaving the optimum size of rib/remnant pillars in the goaf and installing adequate support systems in the working areas. It is observed in the field that rib/remnant pillars, designed with a safety factor of ∼0.17 are found suitable for regular caving of overlying massive strata in the goaf. The side spalling and the strain burst are minimised by installing the glass-reinforced plastic (GRP) bolts and the wire mesh. The uncontrolled caving of the overlying massive strata in the working area is prevented by installing closely spaced two rows of rock bolts at the goaf edge. This study would be helpful to design different underground structures and to ensure the safety of working areas during the extraction of highly stressed coal seams under massive strata.

The influence of mantle hydration and flexure on slab seismicity in the southern Central Andes

Knowledge of the causative dynamics of earthquakes along subduction-zone interfaces and within oceanic slabs is relevant for improving future seismic hazard assessments. Here, we combine the analysis of seismic tomography, the 3D structure of the slab and seismicity to investigate the controlling factors driving slab seismic activity beneath the southern Central Andes. We evaluate the ratio distribution between compressional and shear-wave seismic velocities (Vp/Vs) as a proxy for the hydration state of the lithospheric mantle, oceanic slab, and plate interface. Regions of high Vp/Vs, i.e. areas of hydrated mantle, are principally caused by compaction effects and dehydration reactions. In contrast, slab seismicity in areas of low Vp/Vs and inferred lower fluid content in the overriding plate is facilitated by enhanced flexural stresses due to changes in the subduction angle of the oceanic plate. Plate-interface background seismicity correlates with areas of higher Vp/Vs (hydrous interface) at depths <50 km, while areas of most pronounced plate-locking coincide with regions of low Vp/Vs (anhydrous interface). The regions of anhydrous plate interface are likely candidates for future great megathrust events due to their higher potential for elastic energy accumulation compared to more hydrated regions.

Interwell area design procedure to generate safe zones in rockburst-hazardous conditions of Talnakh deposits

Stoping at rockburst-hazardous deposits Talnakh and Oktyabrsky should be carried out within protected zones to prevent dynamic events induced by rock pressure. Until the 2000s, the main method of generation of safe zones was construction of protection capping by means of advanced cutting of aguard bed in the&nbsp; roof of an ore body. Later on, the destressing drilling method was introduced. This approach to relaxation of ore bodies from stresses ensures formation of a self-developing local destress zone possessing high yielding. The latter prevents accumulation of elastic energy in adjacent rock mass. Borehole erosion transforms round cross-sections to ellipsoids, and, consequently, the width of the interwell space decreases. As the spacing of boreholes reduces, the intensity of failure in the interwell area grows. The borehole destressing technology is used in sulfide ore cutting with backfilling. Effectivization of the borehole destressing technology is discussed. The main stages of this method implementation in rockburst-hazardous mines in the Talnakh ore province are described. The absence of an engineering procedure to calculate drillhole spacing in destress drilling is emphasized. The general provisions of such procedure to take into account the key features of the geomechanical borehole&ndash;interwell area system are substantiated. The approach to determination of critical stresses for deformation to take place in the interwell area is shown. Destress drilling widely uses Solo Sandvik and Simba Atlas Copco drill rigs for ring drilling of holes with diameters of 64&ndash;89 mm.

Thermal gradient and elastic dependence of induced charge electro-osmosis in viscoelastic fluids

Induced charge electro-osmosis has notable implementation possibilities in thermal management and efficient electrokinetic micropumps. We present the coupled numerical implementation around a polarized cylinder subject to an external electric field with the influence of different polymer elasticity and thermal gradients. The azimuthal velocity, flow types, kinetic energy, elastic energy, ion transport behavior, and heat transfer capability are investigated in detail. The results show that the inflow and outflow rates approximately overlap for a typical small voltage limit ϕ &amp;lt; 0.1. The Rayleigh number (Ra) significantly influences the elastic energy accumulation and evolution time to the final steady state. The thermal buoyancy forces are not sufficient to create typical thermogravitational convection with passive heat transfer when Ra &amp;lt; 1.3 × 10−3, resulting in heat diffusion and electro-osmosis velocity dominating the temperature distribution. The Nusselt number (Nu) plot with a weak viscoelastic effect implies an asymptotic Nu=0.44+2.65Ra0.35 relation. Relevant results open possibilities for enhanced mixing and heat transfer in microdevices, providing insight into barriers to the non-Newtonian nature of electrokinetic dynamics.

Classification of Coal Bursting Liability Based on Support Vector Machine and Imbalanced Sample Set

As an inherent property of the accumulation of elastic energy and the sudden instability failure of coal, coal bursting liability (CBL) is the basis of the research on the early warning and prevention of coal burst. To accurately classify the CBL level, the support-vector-machine (SVM) method was introduced in this paper, and the dynamic failure time (DT), elastic energy index (WET), impact energy index (KE) and uniaxial compressive strength (RC) were selected as the classification indexes. An imbalanced sample set, containing 95 groups of measured data of CBL, was established, and eight SVM classification models were constructed, based on different kernel functions and swarm-intelligence-optimization algorithms. Focusing on the problem of sample imbalance, the classification accuracy, A, F1-score and kappa coefficient were used to comprehensively evaluate the classification performance of SVM models, and the grey-wolf-optimizer SVM (GWO-SVM) model was selected as the best model in this paper, reaching the highest accuracy of 98.9%. The GWO-SVM was applied to identify the CBL level of the 4# coal seam in Xiaozhuang Coal Mine and the 1# coal seam in the Wanfeng Coal Mine. The results of the engineering application are consistent with those from the engineering field, and show that the proposed model is scientific and practical, and can be a new method for CBL classification.

Research on Splitting-Tensile Properties and Failure Mechanism of Steel-Fiber-Reinforced Concrete Based on DIC and AE Techniques.

Concrete presents different internal micro-structure and damage characteristics because of the different content of steel fibers and the randomness of its distribution. Therefore, the failure process of steel-fiber-reinforced concrete (SFRC) should be divided into different stages and the damage types should be classified to further clarify the strengthening mechanism of steel fibers. The role of volume fractions of steel fibers in the splitting-tensile strength of concrete was investigated by split tensile tests for concrete with four different volume fractions of steel fibers (0.0%, 1.0%, 1.5%, 2.0%). The acoustic emission energy and horizontal displacement of concrete in the splitting-tensile process were monitored by combing digital image correlation (DIC) and acoustic emission (AE) techniques, and the microscopic failure mechanism of SFRC was analyzed emphatically. The results showed that the addition of steel fibers improved the splitting-tensile strength of concrete. With the increase of the volume fraction of steel fibers, the splitting-tensile strength of concrete increased first and then decreased, and reached the maximum value of 5.294 MPa when the content was 1.5%. It was observed that the overall failure mechanism could be divided into four stages: slow accumulation of elastic energy (I); rapid accumulation of elastic energy (II); rapid accumulation of dissipated energy (III); a slow decrease of elastic energy and a slow increase of dissipated energy (IV). Tensile failure dominated the failure process of concrete splitting-tensile resistance, while there was a part of shear failure.

The mechanics of plastic volumetric deformation of rock and the rockburst mechanism

Relevance and problematics. The problem of rock pressure dynamic manifestations, primarily rockbursts and tectonic shocks, is particularly acute for both coal fields and ore deposits. Dynamic manifestations of rock pressure lead to injury and death, to kilometers of destroyed mine workings, loss of minerals, business interruption and additional costs for forecast and prevention. However, these geomechanical phenomena seem to be the most unexplored. They have been studied purely at the empirical level. This is due to poor understanding of the elastic energy accumulation and release mechanism in dynamic phenomena. Methods of research. The proposed model of plastic deformation of rock and the resulting mechanism of rockbursts and tectonic shocks, impacts and earthquakes are based on analytical criteria for rock plasticity and strength, confirmed by a large amount of experimental data. Results, their analysis and recommendations for use. Based on the previous studies performed by the author, a new model of plastic deformation of rocks at the stage of deformation strengthening is proposed. Based on this model, the mechanism of rock plastic deformation, the mechanism of fractured block media destruction and accumulation of deformation energy by rocks are substantiated. It is shown that blocks of various ranks turning leads to deformation energy accumulation in the rock mass. The energy is accumulated both in the blocks and in the surrounding. Conclusions. The proposed model of rockburst and other dynamic phenomena, as well as block mass strength criterion, made it possible to obtain a burst hazard criterion in an analytical form for the first time. The fracturing (blocking) role and contribution to the rockburst mechanism has been shown for the first time. Comparison of the proposed burst hazard criterion with an empirical analogue shows good convergence.

On the serration evolution of cellular bulk metallic glass monitored by fractal analysis

Cellular bulk metallic glasses (BMGs) with varying porosities were fabricated by laser drilling, demonstrating different modes for the mechanical energy absorption process. The evolution of the elastic energy accumulation rate (Ep) and load drop parameter (L' = |d(load)/d(t)|) during the plastic-flow stages was examined using statistical analysis. The results have shown that the distribution of load drops follows a power-law scaling, and the three-parameter Weibull moduli (m) of both the Ep and L' values have fractal nature during the deformation process. The fractal dimension (D), fractal character measurement parameter (M) and fractal iteration sequence of the Weibull moduli (mEp−εp and mL′−εp) were used to characterize the serration evolution behavior under different conditions. The differences and relationships between the Ep and L' values were also discussed. The cellular BMG with stable and more iterative fractal sequences tend to exhibit relatively-stable deformation behavior, linearly growth energy absorption process and larger macroscopic plasticity.

Analytical Modeling of a New Compliant Microsystem for Atherectomy Operations.

This work offers a new alternative tool for atherectomy operations, with the purpose of minimizing the risks for the patients and maximizing the number of clinical cases for which the system can be used, thanks to the possibility of scaling its size down to lumen reduced to a few tenths of mm. The development of this microsystem has presented a certain theoretical work during the kinematic synthesis and the design stages. In the first stage a new multi-loop mechanism with a Stephenson’s kinematic chain (KC) was found and then adopted as the so-called pseudo-rigid body mechanism (PRBM). Analytical modeling was necessary to verify the synthesis requirements. In the second stage, the joint replacement method was applied to the PRBM to obtain a corresponding and equivalent compliant mechanism with lumped compliance. The latter presents two loops and six elastic joints and so the evaluation of the microsystem mechanical advantage (MA) had to be calculated by taking into account the accumulation of elastic energy in the elastic joints. Hence, a new closed form expression of the microsystem MA was found with a method that presents some new aspects in the approach. The results obtained with Finite Element Analysis (FEA) were compared to those obtained with the analytical model. Finally, it is worth noting that a microsystem prototype can be fabricated by using MEMS Technology classical methods, while the microsystem packaging could be a further development for the present investigation.

Energy evolution and distribution law of rock under thermal mechanical coupling

The characteristics of the energy evolution and distribution of rock during deformation and failure were studied based on thermal mechanical coupling tests completed by Min Ming at his Master?s thesis in 2019. Dissipated energy is greater than elastic energy at the crack closure stage, while elastic energy is dominant at the linear elastic stage. At the post-peak failure stage, elastic energy is released rapidly before 800?C and released slowly at 1000?C. A comprehensive evaluation index to examine the influence of temperature on rock strength and deformation ability was proposed from the perspective of elastic energy accumulation ability. The negative effect of temperature on the strength of the rock sample is weaker than that on the elastic modulus before 400?C. The negative effect of temperature on the strength of the rock sample is stronger than that on the elastic modulus after 600?C.

On the fractal analysis of the serration behavior of a bulk metallic glass composite

In this work, the plastic-flow dynamics of a Zr48Cu47.5Al4Co0.5 (at.%) bulk metallic glass composite (BMGC) under varying strain rates and stress gradients were investigated. Statistical analysis on the distributions of the elastic energy accumulation rates (Ep) and L' values (L' = |d(load)/d(t)|) was conducted. A self-similar structure was observed in the distribution of the plastic-flow serrations, including the serration shape and the L' value. The three-parameter Weibull moduli of both Ep and L' values of the plastic flows have shown that the Ep values can have a relatively high uniformity while the L' values demonstrate intrinsic large variations. The fractal dimensions of both the Ep and L' values are dependent on applied strain rates and stress gradients. During the evolution of plastic flows, the Weibull moduli of both Ep and L' values decreased with the increasing of plastic strains, regardless of varying strain rates and stress gradients. Moreover, the relationships between the elastic energy accumulation and release processes were also discussed. The present findings not only shed more light on the plastic-flow dynamics of BMGCs, but also open up a window for uncovering the underlying mechanisms of the serration behavior of related solid materials.