Degradation Coefficient Research Articles

Spherical Aberration and Scattering Compensation in Microscopy Images through a Blind Deconvolution Method.

The optical quality of an image depends on both the optical properties of the imaging system and the physical properties of the medium the light passes while travelling from the object to the image plane. The computation of the point spread function (PSF) associated to the optical system is often used to assess the image quality. In a non-ideal optical system, the PSF is affected by aberrations that distort the final image. Moreover, in the presence of turbid media, the scattering phenomena spread the light at wide angular distributions that contribute to reduce contrast and sharpness. If the mathematical degradation operator affecting the recorded image is known, the image can be restored through deconvolution methods. In some scenarios, no (or partial) information on the PSF is available. In those cases, blind deconvolution approaches arise as useful solutions for image restoration. In this work, a new blind deconvolution method is proposed to restore images using spherical aberration (SA) and scatter-based kernel filters. The procedure was evaluated in different microscopy images. The results show the capability of the algorithm to detect both degradation coefficients (i.e., SA and scattering) and to restore images without information on the real PSF.

Biodiversity and suppression of wood-decaying fungi in marine environment, Alexandria, Egypt by selected natural products: Control the fungal growth/contamination

The current study investigated the biodiversity and control of wood-decaying fungi isolated from marine environment, at Alexandria, Egypt. The fungal growth was in vitro control via selected plant natural products (seaweeds and aromatic herbs). Among 45 marine fungal isolates from decaying-wood samples were detected. At 85% similarity level, 5 clusters (A, B, C, D, and E) were obtained. According to numerical classification, one strain from each cluster was identified based on the sequences of ITS-PCR. The species level because their best matched references from BLAST search were higher than 96% of similarities with ITS sequences obtained from GenBank (four Aspergillus and one Penicillium species as the most abundant isolates). Additionally, the enzymatic action of cellulase, amylase, protease, and lipase was detected by fungal isolates. The highest enzymatic degradation coefficient (EDC) was of 1.38 for lipase secreted by P. chrysogenum strain HGM3. Only three strains (A. sydowi strain HGM1, P. chrysogenum strain HGM3 and A. amstelodami strain HGM5) produced cellulase enzyme with EDC value (1.075, 1.27 and 1.08), respectively. Moreover, the methanolic extracts of Ulva lactuca and Corallina officinalis collected from the Egyptian coasts besides aromatic plant; Salvia. officinalis purchased from herbal market were qualitatively analyzed using Gas chromatographic mass spectra. Various organic crude extracts exhibited that there were different types of high and low molecular weight bioactive compounds. Most of them are basically biologically important. Thus the identification of a good number of compounds in various crude extracts of seaweeds and herbal plants might have potent ecological role.

Analysis of parameters of purine metabolism in patients with diabetes mellitus type 2

The aim of this research is to comprehensively analyze the current state of purine metabolism as well as assess its features in patients with diabetes mellitus type 2, taking into account the clinical and metabolic polymorphism of the disease. The authors examined 327 patients with diabetes mellitus type 2 (144 men and 183 women), a group of individuals with an average age of 57.8±10.1 years. The average duration of the disease was (9.3±7.3) years. All subjects received oral hypoglycemic therapy. The researchers determined anthropometric indicators, indicators of carbohydrate metabolism, concentration of creatinine, uric acid, parameters of the blood lipid spectrum, purine bases, activity of xanthine oxidase and hypoxanthine-guanine-phosphoribosyltransferase in the blood. In the course of the study the authors verified excretion of uric acid and creatinine renal uric acid, fractional clearance of uric acid, total tubular reabsorption of uric acid and coefficient of complete degradation of purine bases. Using the software complex "Statgraphics Centurion 18.0", we statistically analyzed the obtained data. The research showed that a decrease in assimilation, increased oxidation of purine bases due to the activation of xanthine oxidase, and a decrease in their reutilization by inhibiting the activity of hypoxanthine-guanine-phospho­ribo­syltransferase cause the high intensity of purine catabolism in patients with diabetes mellitus type 2. Hyperuricemia (28.0%), increased creatinine renal uric acid (62.3%), increased coefficient of complete degradation of purine bases (41.6%), activity of xanthine oxidase (38.8%) and inhibition of hypoxanthine-guanine-phosphoribosyltransferase activity (50.3%) dominate in the structure of disorders of purine bases in patients with diabetes mellitus type 2. We found that more than 50% of the subjects had high concentrations of purine bases in the blood. Purine bases concentrations in the blood of patients with diabetes mellitus type 2 closely correlate with each other and with the activity of xanthine oxidase and do not correlate with the level of uricemia, the level of uricemia does not correlate with the level of uric acid excretion. That is, the concentration of uric acid in the blood of patients with diabetes mellitus type 2 does not objectively reflect its production in the body. Patients with diabetes mellitus type 2 with obesity associate hyperuricemia with significantly lower creatinine renal uric acid and fractional clearance of uric acid as well as activation of the anabolic pathway of purine bases deposition.

Effective construction of Cu, S-CQDs/BiVO4 composites through a facile and efficient route

Monoclinic bismuth vanadate (m-BiVO4) is a well-known photocatalytic material. However, its poor charge transport and photogenerated electron hole rapid recombination limit the application of m-BiVO4. In this paper, we successfully constructed a novel copper-sulfur co-doped carbon quantum dots (Cu, S-CQDs)/BiVO4 nanocomposite through a facile and efficient route, which significantly improved the photocatalytic performance of BiVO4. The physicochemical properties of Cu, S-CQDs and Cu, S-CQDs/BiVO4 samples were studied by various characterization. It was concluded from the degradation experiments that the photocatalytic degradation rate of rhodamine B reaches 99% in 60 min under natural light. The degradation curve compounds the quasi-primary kinetic model, and the kinetic coefficient of degradation is 0.07831 min−1, which is 5.37 times than that of pure BiVO4. Moreover, the free radical scavenging experiments reveal that the hole and superoxide radicals play a major role in the photocatalysis process. After four cycles, the activity of photocatalyst exhibits high stability, which is extremely important for the photocatalytic process. In the summery, the prepared Cu, S-CQDs/BiVO4has many advantages, such as environmental-friendly, low cost and a wide range of applications.

Multi‐indicator evaluation method of important members of truss string structures

SummaryDuring the past decade, the progressive collapse of structures has received growing attention, and the study of member importance is a key step for investigating the progressive collapse resistance. However, traditional methods for evaluating the member importance usually employ a single indicator, and when multiple indicators are involved, different indicators may generate different member rankings. Moreover, the truss string structure is a multiple super‐stationary structure with many members, and the current studies mainly focus on cable failure, which does not mean that other members are not important. In this study, the initial selection of important members is first performed based on concept evaluation, and then, the alternate path method is used to analyze the progressive collapse resistance of truss string structures; the slope degradation coefficient γ of incremental dynamic analysis curve, load capacity degradation coefficient β, and nested load capacity degradation coefficient β′ are introduced; and the sensitivity coefficient SIj and fragility coefficient VIi are defined with axial force as the structural response. Based on the above five indicators, two cases are conducted to evaluate the member importance. The analysis results show that the cable and the bottom chord member at the support are evaluated as the first‐level important members. Through the analysis of different indicators, it is found that the regularity of the coefficient of each member is inconsistent for different indicators. The results could be one‐sided if the important members were evaluated by a single indicator only. In addition, the second‐level important members of truss string structures are evaluated by multi‐indicator analysis. Finally, the nominal progressive collapse resistance of truss string structures is given based on the importance coefficient of the first‐ and second‐level important members.

A Numerical Investigation Concerning the Effect of Step-Feeding on Performance of Constructed Wetlands Operating under Mediterranean Conditions

The effects of wastewater step-feeding (SF) on the performance of horizontal subsurface flow constructed wetlands (HSF CWs) are numerically investigated. The purpose is to check if this alternative feeding technique increases the ability of HSF CWs to remove pollutants. Two methodologies are used: Initially, the tanks-in-series (TIS) methodology, based on the finite volume method (FVM), is analyzed using the volumetric degradation coefficient λ. In this case, the operation of a CW is similar to a series of continuous stirred-tank reactors (CSTRs) operating under steady conditions. Then, the step-feeding (SF) procedure is presented, in which the CW is operated like a plug flow reactor (PFR). For the numerical investigation, the available experimental data for five existing HSF CWs are used. The results show that SF does not improve the performance of HSF CWs in removing biochemical oxygen demand (BOD) operating under Mediterranean conditions. When the HSF CWs operate without the SF procedure, the performance is between 55 and 81% for the TIS method and 60 and 89% for the PFR method, while the ability of the CW tank to remove the BOD decreases and varies from 48 to 79% (TIS) and from 54 to 86% (PFR), respectively.

Gear wear prediction based on the theorem of degradation entropy generation

Tooth surface material loss caused by gear wear alters the surface morphology of gears, which impacts their vibration, noise, and remaining lifespan. Although gear wear modeling and prediction have been extensively studied, this paper proposes a novel approach based on the theorem of degradation entropy generation (DEG). A point-by-point calculation method is introduced to determine the degradation coefficient for each measurement point on the tooth profile, accounting for varying working conditions along the tooth profile during the actual meshing process of the gear pair. First, the FZG gear’s bearing capacity is tested. Next, a surface roughness profilometer is employed to in-situ measure the tooth profile after each load stage. The profile deviation curve and the amount of profile wear following each load stage are obtained by processing the measured profile morphology data. Then, the pitting safety factor for each point on the tooth surface is calculated according to the ISO 6336–22:2018 standard and used to correct the degradation coefficient for that point. Finally, the entropy generation of the system during each load stage of the FZG gear is calculated. The degradation coefficient suggested in the DEG theorem is employed to link gear wear with system entropy generation, realizing gear wear modeling and prediction. The results demonstrate that the gear wear calculation method based on the DEG theorem can accurately predict the evolution of tooth profile surface morphology during the experimental process. This research provides a unified calculation method for surface morphology evolution caused by gear wear during service.

How far do indirect signal production mechanisms influence regularity in the three-dimensional Keller–Segel–Navier–Stokes system?

This paper reconsiders the Keller–Segel–Navier–Stokes model with indirect signal production and weak logistic-type degradation in a three-dimensional (3D) bounded and smooth domain. One recent literature has asserted that for all reasonably regular initial data, the associated initial-boundary value problem with certain sub-quadratic degradation possesses at least one global generalized solution which is uniformly bounded and converges to the constant equilibrium in [Formula: see text] with any [Formula: see text]. Nevertheless, the knowledge on regularity properties of solution has not yet exceeded some information on fairly basic integrability features. The present study firstly elevates the regularities of some solution components under the same assumption on degradation exponent, especially establishes the global boundedness in [Formula: see text] with [Formula: see text], and secondly asserts that each of these generalized solutions becomes eventually classical and bounded in [Formula: see text] under some suitably strong sub-quadratic degradation assumption and an explicit smallness condition on the intrinsic growth rate of cells relative to some powers of the degradation coefficient. As a by-product of the latter, these solutions are shown to stabilize toward the corresponding spatially homogeneous state in [Formula: see text]. Our results indeed provide a more in-depth understanding on the global dynamics of solutions, and significantly improve previously known ones. In comparison to the related contributions in the case of direct signal production, our findings inter alia rigorously reveal that the indirect signal production mechanism results in some genuine regularizing effects in the sense that the possibly destabilizing action of chemotactic cross-diffusion in the 3D Keller–Segel–Navier–Stokes system can be greatly weakened or even completely excluded by this indirectness.

Numerical simulation of water environment capacity from wet, normal, and dry years: taking the Luo River as an example

Abstract Water pollution is a globally significant issue. Water environment simulation is an important tool to study water pollution. In order to investigate the impact of hydrological periods, water quality indicators and cross-sections on the water environment capacity, we took the Luo River in Luoyang City as an example, and used MIKE21-coupled hydrodynamic and water quality model and the segmentation method to calculate the water environment capacity of COD, TP, and NH3-N in wet, normal, and dry periods under L1 (Gao Yazhai-Lilou), L2 (Li Lou-Baimasi), and L3 (Baimasi-G207 Highway Bridge) section. The results of the study showed that from the hydrological period, the water environmental capacity was the largest in the wet period due to the dilution effect caused by higher precipitation; from the water quality indexes, the COD concentration was the largest due to industrial pollution, but the higher degradation coefficients result in the largest water environment capacity for COD; from the cross-section, L1 has the longest channel, thus the highest capacity of the water environment was L1. This result can broaden ideas for the application of the MIKE21 model, provide a basis for the calculation of the dynamic water environment capacity and water pollution control in the river.

Long‐Term In Situ Performance Comparison of Si and GaAs Solar Arrays in Medium Earth Orbit

The present work analyzes the long‐term in situ comparison of Si and GaAs solar array based on two BeiDou Navigation Satellite System satellites in medium Earth orbit (MEO). From the 6 year long‐term perspective, both Si and GaAs solar arrays exhibit significant yearly periodic variations in remote sensing current and temperature due to periodic variations in the Sun–satellite distance. The practical in situ photogenerated current degradation of Si and GaAs solar arrays in MEO orbits is analyzed by the light intensity and working temperature after calibrating. The annual degradation coefficients of Si and GaAs solar arrays are calculated to be 0.986 and 0.990, respectively, which means 13.2% and 9.6% current degradation for Si and GaAs solar arrays at the end of the 10 year life MEO satellite. Also, this article examines the temperature of the MEO orbit, with the working temperature ranging from −144.7 to 56.3 °C for Si solar array and −136.9 to 60.9 °C for GaAs solar array. The present work provides a critical accurate degradation parameter for the MEO satellite's precise design and the space application of the low‐cost silicon solar cell.

Finite Element Analysis and Parametric Study of Panel Zones in H-Shaped Steel Beam–Column Joints

This paper investigates the mechanical properties of a traditional welded rigid joint with a weakened panel zone under seismic load. The created finite element model is calibrated by the high-strength steel joint test, carried out by the team in the early stage, and the effectiveness of the finite element method was verified. The finite element software ABAQUS is used to investigate the influence of different joint web thicknesses on the mechanical properties of middle column joints under a low-cyclic-loading test. Supported by a validated numerical model, the ductility, energy dissipation, and other properties of different thicknesses of panel zone column webs are carefully analyzed. The results indicate that the thickness of the web plate in the panel zone significantly affects the location of the joint plastic hinge. The ultimate loading capacity of the joints increased significantly with an increase in the thickness of the webs in the panel zones. Compared with the joint with a weakened panel zone, the hysteresis curve of the strengthened joint is fuller; meanwhile, it cannot alleviate the stress concentration at the weld holes of the web. When the thickness of the joint domain web is too weak, excessive deformation in the joint domain will lead to a decrease in the bearing capacity of the joint, causing damage. The stiffness degradation coefficient of the web-thickened specimen was found to be dominated and controlled by the stiffness of the beam; however, with an increase in the thickness of the web, the stiffness degradation coefficient remained basically unchanged. Finally, a recommendation for weakened beam–column interior joints based on the steel frame panel zone is made, which will lay a foundation for the simulation and analysis of the seismic performance of this structure.

Analytical investigation of hygrothermal effects on failure mechanisms of adhesively bonded corrugated sandwich structures under three-point bending

This research paper presents an analytical mechanics model for studying the degraded failure mechanics of an adhesively bonded corrugated sandwich structure (ABCSS) subjected to three-point bending and hygrothermal ageing loads. The model incorporates a detailed stress state model that considers the stress distribution of the adhesive layer, including the adhesive fillet, to more accurately reflect the failure mechanics of ABCSS. The Fickian Diffusion model and a degradation coefficient are used to describe the characteristics of water diffusion and hygrothermal mechanical degradation for the adhesive joint in ABCSS. The hygrothermal ageing experiments are conducted by immersing the ABCSS into deionized water and 5 wt% NaCl water, followed by three-point bending tests after hygrothermal ageing. The proposed two-step finite element (FE) method is developed to simulate both moisture diffusion and three-point bending test. The presented FE method is validated through comparison with corresponding experimental results, then it is utilized to demonstrate that the proposed analytical model is accurate enough in initial failure modes and initial failure loads predictions. At last, the hygrothermal effects on degraded stress distribution and degraded failure performance are investigated through analytical method, and the degraded failure mechanics maps are constructed to further visually demonstrate failure mechanics with the aid of the analytical model.

Influences of fatigue stiffness degradation of in-service concrete T-beams on natural vibration frequency

ABSTRACT In order to obtain the fatigue stiffness degradation law of in-service concrete T-beam and carry out fatigue life prediction, a dual-stage stiffness degradation model considering cracks was established for T-beams and formulas for calculating the fundamental frequency of damaged concrete T-beams were deduced based on relevant theories of damage mechanics. The developed model aimed to investigate the influences of the fatigue stiffness degradation of in-service concrete T-beams on the natural vibration frequency of structures. A fatigue test was conducted for full-scale test beams to examine the crack development and fundamental frequency change law of structures during the fatigue process. Based on a full scale model of 10 m reinforced concrete T-beams, static and fatigue failure tests were carried out to obtain the evolution law of fatigue residual stiffness with load times. Fatigue damage coefficient D and stiffness degradation coefficient k were introduced to establish the fatigue life prediction model of T-beams in service. In line with the related test data and fundamental frequency formulas, stiffness updating methods were put forward for the concrete T-beam finite element models. By comparing the calculated value and test value of the natural vibration frequency of structures, the relative error was estimated to be within 6%. This verified the accuracy and reliability of the fundamental frequency calculation formulas and the updated finite element models. The research results can be used as a reference for the precise simulation of the fatigue damage finite element models of concrete T-beams. Finally, a method for life prediction of in-service reinforced concrete beam Bridges is proposed, and relevant research results can provide theoretical support for the study of life prediction of such Bridges.

Assessing the environmental destruction in forest ecosystems using landscape metrics and spatial analysis

Forest degradation is a serious environmental issue that has significant implications for ecological stability, biodiversity, and human well-being. Identifying the extent and severity of forest degradation is crucial for effective management and conservation of forest ecosystems. The objective of this study was to assess the ecological vulnerability of the forest in the Dadabad region using spatial analysis and landscape metrics. The land cover map of the area was divided into 13 sub-basins to quantify landscape metrics, and the severity of human activities, degradation level, and ecological vulnerability were calculated for each sub-basin. Each sub-basin was evaluated as a single landscape to determine the extent of degradation, and landscape zoning was performed based on the degradation coefficients. The study found that sub-basins 2 and 4 had the highest levels of degradation, while sub-basins 3, 7, 8, 11, and 12 were the least degraded. Over half of the Dadabad region, 37.8% for protection and 32.25% for rehabilitation, was recommended for conservation planning. The research highlights the importance of using spatial analysis of landscape metrics to assist managers and planners in protecting and conserving natural areas.

Significance of temperature as a key driver in ZVI PRB applications for PCE degradation

We report on the potential of elevated groundwater temperatures and zero-valent iron permeable reactive barriers (ZVI PRBs), for example, through a combination with underground thermal energy storage (UTES), to achieve enhanced remediation of chlorinated hydrocarbon (CHC) contaminated groundwater. Building on earlier findings concerning deionized solutions, we created a database for mineralized groundwater based on temperature dependence of tetrachloroethylene (PCE) degradation using two popular ZVIs (i.e., Gotthart–Maier cast iron [GM] and ISPAT sponge iron [IS]) in column experiments at 25 °C–70 °C to establish a temperature-dependent ZVI PRB dimensioning approach. Scenario analysis revealed that a heated ZVI PRB system in a moderate temperature range up to 40 °C showed the greatest efficiency, with potential material savings of ~55% to 75%, compared to 10 °C, considering manageability and longevity. With a 25 °C–70 °C temperature increase, rate coefficients of PCE degradation increased from 0.4 ± 0.0 h−1 to 2.9 ± 2.2 h−1 (GM) and 0.1 ± 0.1 h−1 to 1.8 ± 0.0 h−1 (IS), while TCE rate coefficients increased from 0.6 ± 0.1 h−1 to 5.1 ± 3.9 h−1 at GM. Activation energies for PCE degradation yielded 32 kJ mol−1 (GM) and 56 kJ mol−1 (IS). Temperature-dependent anaerobic iron corrosion was key in regulating mineral precipitation and passivation of the iron surface as well as porosity reduction due to gas production.

Research on the purification enhancement of ecological ponds: Integrating water cycle optimization and plants layout

The hydrodynamic conditions of ponds are generally poor, which seriously affects the long–term water quality guarantee. In this research, the numerical simulation method was used to establish an integrated model of hydrodynamics and water quality for the simulation of the plant purification effect in ponds. Based on the flushing time using the tracer method, the purification rate of plants was introduced to consider the purification effect of plants on water quality. In–situ monitoring was carried out at the Luxihe pond in Chengdu, and the model parameters such as the purification rate of typical plants were calibrated. The degradation coefficient of NH3–N in the non–vegetated area was 0.014 d−1 in August and 0.010 d−1 in November. In areas with vegetation, the purification rate of NH3–N was 0.10–0.20 g/(m2·d) in August and 0.06–0.12 g/(m2·d) in November. The comparison of the results in August and November showed that due to the higher temperature in August, the plant growth effect was better, and the degradation rate of pollutants and the purification rate of pollutants by plants were higher.The flushing time distribution of the proposed Baihedao pond under the conditions of terrain reconstruction, water replenishment, and plant layout was simulated, and the frequency distribution curve of flushing time was used to evaluate the results. Terrain reconstruction and water replenishment can significantly improve the water exchange capacity of ponds. The reasonable planting of plants can reduce the variability of the water exchange capacity. Based on this combined with the purification effect of plants on NH3–N, the layout plan of Canna, Cattails, and Thalia in ponds was proposed.

Triaxial compression experiment and damage constitutive model of microbially modified strongly weathered phyllite

Microbial improvement of strongly weathered phyllite roadbed can effectively solve the problems of insufficient filling and waste soil in roadbed construction while protecting the environment and considering economic benefits. This paper uses microbially induced carbonate precipitation (MICP) technology to improve the strongly weathered phyllite in the Nanchang area and conducts the porosity and triaxial compression tests on the samples before and after the improvement. According to the strain strength theory of rock and the Druker-Prager yield criterion, the damage constitutive model of the improved sample is established considering the effects of the initial porosity and cementation degradation coefficient on the sample’s mechanical properties. The results show that the strengths of the samples improved by MICP technology are increased by more than 35%, and the porosities are reduced by 15%, which meets the requirements of roadbed filling. The stress–strain curves of the modified samples under triaxial compression can be divided into three stages: elastic stage, elastic–plastic stage and ductile flow stage. The triaxial compression test results of the improved samples show that the damage constitutive model established can describe the stress–strain relationship of the samples well, which verifies the rationality of the model. This model provides a theoretical basis for studying damage softening and mechanical properties of microbially modified strongly weathered phyllite samples.

Comparisons of Load-Based and AHRI 210/240 Testing and Rating for Residential Heat Pumps

The current testing and rating procedure for residential air conditioners and heat pumps is based on a steady-state performance measurement approach with a degradation coefficient to account for cycling losses at part-load conditions. Test equipment performance is measured under various ambient conditions with varying compressor and fan speeds, and the results are propagated through a temperature-bin method to estimate seasonal performance. Although the current rating approach offers a standardized performance metric for comparing the relative performances of different equipment, it involves disabling the native controls and, as a result, does not consider the impact of integrated controls for test units and their dynamic interactions with representative building loads. As an alternative, a load-based testing methodology (CSA EXP07) has been developed in which the dynamic performance of equipment is measured in a test facility by allowing it to respond to a simulated virtual building model. This study compares the steady-state and dynamic load-based performance measurement methodologies for use on a 5-ton residential heat pump system in order to understand the differences and their significance for the next-generation rating procedure. The differences in the two test methodologies' performance evaluation results are discussed with a causal analysis of the observed differences.

Condensation heat and mass transfer characteristics of zeotropic refrigerant mixture R1234yf/R32 inside small-scale tube: Flow patterns observation and non-equilibrium film model calculation

Minichannel heat exchanger has been more and more widely used in refrigeration industry and other fields due to its high heat transfer efficiency, lightweight and low carbon emissions and other advantages. And, the zeotropic mixture R1234yf/R32 with low global warming potential (GWP) is a promising substitute for R410A in commercial refrigeration. In this study, the experiment investigation of condensation heat and mass transfer characteristics of R1234yf/R32 in minichannel test tube (inner diameter (ID) 2 mm) were conducted. The influencing factors including mass flow rate, vapor quality, mass fraction and tube diameter on the mass transfer and heat transfer coefficient (HTC) were discussed in detailed. The flow pattern was taken during condensation experiment. Meanwhile, based on the discussion of flow pattern, thermophysical properties, tube diameter and composition variation in the liquid film and at the vapor-liquid interface, the effects on heat transfer and mass transfer during condensation were analyzed. The calculation results using the non-equilibrium film model considering the mass transfer on both the liquid and vapor sides were compared and agreed well with the experimental HTC with an average deviation of 14.9%. In addition, the heat transfer degradation coefficient (HTDC), vapor-liquid interface temperature and diffusion flux of R32 were reasonably evaluated by the calculation model, and the comparison analysis were conducted with that of ID 4 mm in the previous study.

A Numerical Study of Blast Resistance of Carbon Fiber Reinforced Aluminum Alloy Laminates

In this study, the dynamic responses under blast loading of carbon fiber reinforced aluminum alloy laminates with different curvature radii, different numbers of layers, and different layer directions of carbon fiber under blast loading were compared numerically. The finite element models were built with ABAQUS/Explicit. To calibrate the numerical models, experiments on curved carbon fiber and curved aluminum alloy were modeled, and the numerical results showed good agreement with the experimental data. The calibrated numerical models were used to simulate the dynamic response of cylindrical panels subject to external explosion loading. The stiffness degradation coefficient was introduced to more accurately simulate the failure mode of the composite structures. The deformation and energy absorption of carbon fiber reinforced aluminum alloy laminates under different structural parameters were obtained. These simulation findings can guide the theoretical study and optimal design of carbon fiber reinforced structures subject to external blast loading.