Prediction and optimization of flue pressure in sintering process based on SHAP

Sinter is the core raw material for blast furnaces.Flue pressure,which is an important state parameter,affects sinter quality.In this paper,flue pressure prediction and optimization were studied based on the shapley additive explanation(SHAP)to predict the flue pressure and take targeted adjustment measures.First,the sintering process data were collected and processed.A flue pressure prediction model was then constructed after comparing different feature selection methods and model algorithms using SHAP+extremely random-ized trees(ET).The prediction accuracy of the model within the error range of±0.25 kPa was 92.63%.SHAP analysis was employed to improve the interpretability of the prediction model.The effects of various sintering operation parameters on flue pressure,the relation-ship between the numerical range of key operation parameters and flue pressure,the effect of operation parameter combinations on flue pressure,and the prediction process of the flue pressure prediction model on a single sample were analyzed.A flue pressure optimization module was also constructed and analyzed when the prediction satisfied the judgment conditions.The operating parameter combination was then pushed.The flue pressure was increased by 5.87%during the verification process,achieving a good optimization effect.

A Flexible Smart Healthcare Platform Conjugated with Artificial Epidermis Assembled by Three‑Dimensionally Conductive MOF Network for Gas and Pressure Sensing

The rising flexible and intelligent electronics greatly facilitate the noninvasive and timely tracking of physiological information in telemedicine healthcare.Meticulously building bionic-sensitive moieties is vital for designing efficient electronic skin with advanced cognitive functionalities to pluralistically capture external stimuli.However,realistic mimesis,both in the skin’s three-dimensional interlocked hierarchical structures and synchronous encoding multistimuli information capacities,remains a challenging yet vital need for simplifying the design of flexible logic circuits.Herein,we construct an artificial epidermal device by in situ growing Cu_(3)(HHTP)_(2) particles onto the hollow spherical Ti_(3)C_(2)T_(x) surface,aiming to concurrently emulate the spinous and granular layers of the skin’s epidermis.The bionic Ti_(3)C_(2)T_(x)@Cu_(3)(HHTP)_(2) exhibits independent NO_(2) and pressure response,as well as novel functionalities such as acoustic signature perception and Morse code-encrypted message communication.Ultimately,a wearable alarming system with a mobile application terminal is self-developed by integrating the bimodular senor into flexible printed circuits.This system can assess risk factors related with asthmatic,such as stimulation of external NO_(2) gas,abnormal expiratory behavior and exertion degrees of fingers,achieving a recognition accuracy of 97.6%as assisted by a machine learning algorithm.Our work provides a feasible routine to develop intelligent multifunctional healthcare equipment for burgeoning transformative telemedicine diagnosis.

Binding Energies of Screened Excitons in a Strained(111)-Oriented Zinc-Blende GaN/AlGaN Quantum Well Under Hydrostatic Pressure

We investigate the binding energies of excitons in a strained （111）-oriented zinc-blende GaN/Al0.3 Ga0.7 N quantum well screened by the electron-hole （e-h） gas under hydrostatic pressure by combining a variational method and a selfconsistent procedure. A built-in electric field produced by the strain-induced piezoelectric polarization is considered in our calculations. The result indicates that the binding energies of excitons increase nearly linearly with pressure,even though the modification of strain with hydrostatic pressure is considered, and the influence of pressure is more apparent under higher e-h densities. It is also found that as the density of an e-h gas increases,the binding energies first increase slowly to a maximum and then decrease rapidly when the e-h density is larger than about 1 ×10^11 cm^-2. The excitonic binding energies increase obviously as the barrier thickness decreases due to the decrease of the built-in electric field.

Load Bearing Capacity and Safety Analysis for Strain-hardening Austenitic Stainless Steel Pressure Vessels

By increasing the yield strengths of austenitic stainless steels for pressure vessels with strain hardening techniques,the elastic load bearing capacity of austenitic stainless steel pressure vessels can be significantly improved.Two kinds of strain hardening methods are often used for austenitic stainless steel pressure vessels：Avesta model for ambient temperature applications and Ardeform model for cryogenic temperature applications.Both methods are obtained from conventional design rules based on the linear elastic theory,and only consider the hardening effect from materials.Consequently this limits the applications of strain hardening techniques for austenitic stainless steel pressure vessels because of safety concerns.This paper investigates the effect of strain hardening on the load bearing capacity of austenitic stainless steel pressure vessels under large deformation,based on the elastic-plastic theory.Firstly,to understand the effect of strain hardening on material behavior,the plastic instability loads of a round tensile bar specimen are derived under two different loading paths and validated by experiments.Secondly,to investigate the effect of strain hardening on pressure vessels strength, the plastic instability pressure under strain hardening is derived and further validated by finite element simulations.Further,the safety margin of pressure vessels after strain hardening is analyzed by comparing the safety factor values calculated from bursting tests,finite element analyses,and standards.The researching results show that the load bearing capacity of pressure vessels at ambient temperature is independent of the loading history when the effects of both material strain hardening and structural deformation are considered.Finite element simulations and bursting tests results show that the minimum safety factor of austenitic stainless steel pressure vessels with 5% strain hardening is close to the recommended value for common pressure vessels specified in the European pressure vessel standard.The proposed study also shows that in the strain hardening design of austenitic stainless steel pressure vessels,the calculation for plastic instability pressure could use theoretical formula or finite element analyses based on geometrical dimensions and material property parameters before strain hardening,but a 5%strain should be employed as a design limit.The proposed research can be used for the strain hardening design of austenitic stainless steel pressure vessels safely.

A personalized electronic textile for ultrasensitive pressure sensing enabled by biocompatible MXene/ PEDOT:PSS composite

Flexible,breathable,and highly sensitive pressure sensors have increasingly become a focal point of interest due to their pivotal role in healthcare monitoring,advanced electronic skin applications,and disease diagnosis.However,traditional methods,involving elastomer film-based substrates or encapsulation techniques,often fall short due to mechanical mismatches,discomfort,lack of breathability,and limitations in sensing abilities.Consequently,there is a pressing need,yet it remains a significant challenge to create pressure sensors that are not only highly breathable,flexible,and comfortable but also sensitive,durable,and biocompatible.Herein,we present a biocompatible and breathable fabric-based pressure sensor,using nonwoven fabrics as both the sensing electrode(coated with MXene/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate[PEDOT:PSS])and the interdigitated electrode(printed with MXene pattern)via a scalable spray-coating and screen-coating technique.The resultant device exhibits commendable air permeability,biocompatibility,and pressure sensing performance,including a remarkable sensitivity(754.5 kPa^(−1)),rapid response/recovery time(180/110 ms),and robust cycling stability.Furthermore,the integration of PEDOT:PSS plays a crucial role in protecting the MXene nanosheets from oxidation,significantly enhancing the device's long-term durability.These outstanding features make this sensor highly suitable for applications in fullrange human activities detection and disease diagnosis.Our study underscores the promising future of flexible pressure sensors in the realm of intelligent wearable electronics,setting a new benchmark for the industry.

Mechanical Performance of Bio-inspired Bidirectional Corrugated Sandwich Pressure Shell Under External Hydrostatic Pressure

This paper aims to enhance the compression capacity of underwater cylindrical shells by adopting the corrugated sandwich structure of cuttlebone.The cuttlebone suffers uniaxial external compression,while underwater cylindrical shells are in a biaxial compressive stress state.To suit the biaxial compressive stress state,a novel bidirectional corrugated sandwich structure is proposed to improve the bearing capacity of cylindrical shells.The static and buckling analysis for the sandwich shell and the unstiffened cylindrical shell with the same volume-weight ratio are studied by numerical simulation.It is indicated that the proposed sandwich shell can effectively reduce the ratio between circumferential and axial stress from 2 to 1.25 and improve the critical buckling load by about 1.63 times.Numerical simulation shows that optimizing and adjusting the structural parameters could significantly improve the advantage of the sandwich shell.Then,the hydrostatic pressure tests for shell models fabricated by 3D printing are carried out.According to the experimental results,the overall failure position of the sandwich shell is at the center part of the sandwich shell.It has been found the average critical load of the proposed sandwich shell models exceeds two times that of the unstiffened shell models.Hence,the proposed bio-inspired bidirectional corrugated sandwich structure can significantly enhance the pressure resistance capability of cylindrical shells.

How Does Stacking Pressure Affect the Performance of Solid Electrolytes and All-Solid-State Lithium Metal Batteries?

All-solid-state lithium metal batteries(ASSLMBs)with solid electrolytes(SEs)have emerged as a promising alternative to liquid electrolyte-based Li-ion batteries due to their higher energy density and safety.However,since ASSLMBs lack the wetting properties of liquid electrolytes,they require stacking pressure to prevent contact loss between electrodes and SEs.Though previous studies showed that stacking pressure could impact certain performance aspects,a comprehensive investigation into the effects of stacking pressure has not been conducted.To address this gap,we utilized the Li_(6)PS_(5)Cl solid electrolyte as a reference and investigated the effects of stacking pressures on the performance of SEs and ASSLMBs.We also developed models to explain the underlying origin of these effects and predict battery performance,such as ionic conductivity and critical current density.Our results demonstrated that an appropriate stacking pressure is necessary to achieve optimal performance,and each step of applying pressure requires a specific pressure value.These findings can help explain discrepancies in the literature and provide guidance to establish standardized testing conditions and reporting benchmarks for ASSLMBs.Overall,this study contributes to the understanding of the impact of stacking pressure on the performance of ASSLMBs and highlights the importance of careful pressure optimization for optimal battery performance.

Research on the influences of confining pressure and strain rate on NEPE propellant:Experimental assessment and constitutive model

In order to study the influences of confining pressure and strain rate on the mechanical properties of the Nitrate Ester Plasticized Polyether(NEPE)propellant,uniaxial tensile tests were conducted using the selfmade confining pressure system and material testing machine.The stress-strain responses of the NEPE propellant under different confining pressure conditions and strain rates were obtained and analyzed.The results show that confining pressure and strain rate have a remarkably influence on the mechanical responses of the NEPE propellant.As confining pressure increases(from 0 to 5.4 MPa),the maximum tensile stress and ultimate strain increase gradually.With the coupled effects of confining pressure and strain rate,the value of the maximum tensile stress and ultimate strain at 5.4 MPa and 0.0667 s^(-1)is 2.03 times and 2.19 times of their values under 0 MPa and 0.00333 s^(-1),respectively.Afterwards,the influence mechanism of confining pressure on the NEPE propellant was analyzed.Finally,based on the viscoelastic theory and continuous damage theory,a nonlinear constitutive model considering confining pressure and strain rate was developed.The damage was considered to be rate-dependent and pressuredependent.The constitutive model was validated by comparing experimental data with predictions of the constitutive model.The whole maximum stress errors of the model predictions are lower than 4%and the corresponding strain errors are lower than 7%.The results show that confining pressure can suppress the damage initiation and evolution of the NEPE propellant and the nonlinear constitutive model can describe the mechanical responses of the NEPE propellant under various confining pressure conditions and strain rates.This research can lay a theoretical foundation for analyzing the structural integrity of propellant grain accurately under working pressure loading.

Estimation of compaction grouting pressure in strain softening soils

A new method was proposed to predict the limited compaction grouting pressure for the soft soils. Theoretical basis of the method considered the conical shear failure above the grout bulb. Using the Mohr-Coulomb yield criterion as the initial yield function, the limited compaction grouting pressure was determined, according to the softening elastic-plastic model based on the conventional triaxial compression tests to simulate the strain softening soils. The small strain in the elastic zone and large stain in the plastic zone and the rational yield function for the strain softening phase stage, the analytical solutions to the compaction grouting pressure were presented. The results indicate reasonable agreement and show a good potential of the proposed method for rationally optimizing the design of compaction grouting operations.

Effects of seepage pressure on the mechanical behaviors and microstructure of sandstone

Surrounding rocks of underground engineering are subjected to long-term seepage pressure,which can deteriorate the mechanical properties and cause serious disasters.In order to understand the impact of seepage pressure on the mechanical property of sandstone,uniaxial compression tests,P-wave velocity measurements,and nuclear magnetic resonance(NMR)tests were conducted on saturated sandstone samples with varied seepage pressures(i.e.0 MPa,3 MPa,4 MPa,5 MPa,6 MPa,7 MPa).The results demonstrate that the mechanical parameters(uniaxial compressive strength,peak strain,elastic modulus,and brittleness index),total energy,elastic strain energy,as well as elastic strain energy ratio,decrease with increasing seepage pressure,while the dissipation energy and dissipation energy ratio increase.Moreover,as seepage pressure increases,the micro-pores gradually transform into meso-pores and macro-pores.This increases the cumulative porosity of sandstone and decreases P-wave velocity.The numerical results indicate that as seepage pressure rises,the number of tensile cracks increases progressively,the angle range of microcracks is basically from 50-120to 80-100,and as a result,the failure mode transforms to the tensile-shear mixed failure mode.Finally,the effects of seepage pressure on mechanical properties were discussed.The results show that decrease in the effective stress and cohesion under the action of seepage pressure could lead to deterioration of strength behaviors of sandstone.

Pressure influence on the Stark effect of impurity states in a strained wurtzite GaN/Al_xGa_(1-x)N heterojunction

A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric field by using a simplified coherent potential approximation. Considering the biaxial strain due to lattice mismatch or epitaxial growth and the uniaxial strains effects, we investigated the Stark energy shift led by an external electric field for impurity states as functions of pressure as well as the impurity position, A1 component and areal electron density. The numerical result shows that the binding energy near linearly increases with pressure from 0 to 10 GPa. It is also found that the binding energy as a function of the electric field perpendicular to the interface shows an un-linear red shift or a blue shift for different impurity positions. The effect of increasing x on blue shift is more significant than that on the red shift for the impurity in the channel near the interface. The pressure influence on the Stark shift is more obvious with increase of electric field and the distance between an impurity and the interface. The increase of pressure decreases the blue shift but increases the red shift.

Impact pressure of waves generated by landslides on bank slopes

Impulse waves that are generated by landslides in narrow reservoir areas threaten the stability of buildings and bank slopes.To discuss the action process and evolution law of the wave pressure on bank slopes,a three-dimensional physical model test that considers impulse waves generated by landslides was performed,and factors including landslide width,thickness,slope angles of the sliding surface,and bank slope angle were considered.Based on wave forms on the bank slopes,wave pressure curve characteristics,and peak value,the action process of wave pressure could be divided into the following stages:maximum pulsating pressure stage,wave impact stage(when waves break),and stationary pulsation stage.It was found that wave breaking is dependent on the value of the surf similarity parameterξ.The distribution pattern of impact pressure decays linearly on both sides of the maximum impact pressure point,and the attenuation degree decreases when it attains 40%of the maximum value.Thus,it is proposed that the prediction formula for the maximum effective impact pressure of the bank slope be related to the reciprocal of wave steepness,relative water depth,and slope rate.The prediction formula provides strong theoretical support for early safety warning and for predicting the bank slope under impulse waves generated by landslides.

Ultra-broadband microwave absorber and high-performance pressure sensor based on aramid nanofiber,polypyrrole and nickel porous aerogel

Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.

Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism

Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground engineering.To reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength combinations.The mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is proposed.The influence of strength combinations on PSCs in the progressive failure process are emphasized.The results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical properties.As the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture behaviors.The PSC flow model is initially validated by the relationship between the accumulated charges of different parts.The results are expected to provide a new reference and method for mining design and roadway quality assessment.

Emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure

Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.

Driving pressure in mechanical ventilation:A review

Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed.

Reservoir quality evaluation of the Narimba Formation in Bass Basin,Australia:Implications from petrophysical analysis,sedimentological features,capillary pressure and wetting fluid saturation

The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography and sedimentological studies,reservoir quality and fluid flow units from derivative parameters,and capillary pressure and wetting fluid saturation relationship.Textural and diagenetic features are affecting the reservoir quality.Cementation,compaction,and presence of clay minerals such as kaolinite are found to reduce the quality while dissolution and secondary porosity are noticed to improve it.It is believed that the Narimba Formation is a potential reservoir with a wide range of porosity and permeability.Porosity ranges from 3.1%to 25.4%with a mean of 15.84%,while permeability ranges between 0.01 mD and 510 mD,with a mean of 31.05 mD.Based on the heterogenous lithology,the formation has been categorized into five groups based on permeability variations.Group I showed an excellent to good quality reservoir with coarse grains.The impacts of both textural and diagenetic features improve the reservoir and producing higher reservoir quality index(RQI)and flow zone indicators(FZI)as well as mostly mega pores.The non-wetting fluid migration has the higher possibility to flow in the formation while displacement pressure recorded as zero.Group II showed a fair quality reservoir with lower petrophysical properties in macro pores.The irreducible water saturation is increasing while the textural and digenetic properties are still enhancing the reservoir quality.Group III reflects lower quality reservoir with mostly macro pores and higher displacement pressure.It may indicate smaller grain size and increasing amount of cement and clay minerals.Group IV,and V are interpreted as a poor-quality reservoir that has lower RQI and FZI.The textural and digenetic features are negatively affecting the reservoir and are leading to smaller pore size and pore throat radii(r35)values to be within the range of macro,meso-,micro-,and nano pores.The capillary displacement pressure curves of the three groups show increases reaching the maximum value of 400 psia in group V.Agreement with the classification of permeability,r35 values,and pore type can be used in identifying the quality of reservoir.

Amendment on the strain measurement of thin-walled human skull shell as intracranial pressure changes

The human skull, composed of tabula extema, tabula intema, and a porous diploe sandwiched in between, is deformed with changing intracranial pressure （ICP）. Because the human skull＇s thickness is only 6 mm, it is simplified as a thin-walled shell. The objective of this article is to analyze the strain of the thin-wailed shell by the stress-strain calculation of a human skull with changing ICP. Under the same loading conditions, using finite element analysis （FEA）, the strains of the human skull were calculated and the results were compared with the measurements of the simulative experiment in vitro. It is demonstrated that the strain of the thin-walled shell is totally measured by pasting the one-way strain foils on the exterior surface of the shell with suitable amendment for data. The amendment scope of the measured strain values of the thin-walled shell is from 13.04% to 22.22%.

An adaptive physics-informed deep learning method for pore pressure prediction using seismic data

Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum engineering.Recent deep learning technique has been receiving more interest due to the great potential to deal with pore pressure prediction.However,most of the traditional deep learning models are less efficient to address generalization problems.To fill this technical gap,in this work,we developed a new adaptive physics-informed deep learning model with high generalization capability to predict pore pressure values directly from seismic data.Specifically,the new model,named CGP-NN,consists of a novel parametric features extraction approach(1DCPP),a stacked multilayer gated recurrent model(multilayer GRU),and an adaptive physics-informed loss function.Through machine training,the developed model can automatically select the optimal physical model to constrain the results for each pore pressure prediction.The CGP-NN model has the best generalization when the physicsrelated metricλ=0.5.A hybrid approach combining Eaton and Bowers methods is also proposed to build machine-learnable labels for solving the problem of few labels.To validate the developed model and methodology,a case study on a complex reservoir in Tarim Basin was further performed to demonstrate the high accuracy on the pore pressure prediction of new wells along with the strong generalization ability.The adaptive physics-informed deep learning approach presented here has potential application in the prediction of pore pressures coupled with multiple genesis mechanisms using seismic data.

High strain rate compressive strength behavior of cemented paste backfill using split Hopkinson pressure bar

The stability of cemented paste backfill(CPB)is threatened by dynamic disturbance,but the conventional low strain rate laboratory pressure test has difficulty achieving this research purpose.Therefore,a split Hopkinson pressure bar(SHPB)was utilized to investigate the high strain rate compressive behavior of CPB with dynamic loads of 0.4,0.8,and 1.2 MPa.And the failure modes were determined by macro and micro analysis.CPB with different cement-to-tailings ratios,solid mass concentrations,and curing ages was prepared to conduct the SHPB test.The results showed that increasing the cement content,tailings content,and curing age can improve the dynamic compressive strength and elastic modulus.Under an impact load,a higher strain rate can lead to larger increasing times of the dynamic compressive strength when compared with static loading.And the dynamic compressive strength of CPB has an exponential correlation with the strain rate.The macroscopic failure modes indicated that CPB is more seriously damaged under dynamic loading.The local damage was enhanced,and fine cracks were formed in the interior of the CPB.This is because the CPB cannot dissipate the energy of the high strain rate stress wave in a short loading period.