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Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels
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作者 Yong-Pan Duan Run-Qiang Chi +1 位作者 Bao-Jun Pang Yuan Cai 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期58-72,共15页
Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris environment.We analyzed the damage to composite overwrapped pressure vessels(COPVs)in ... Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris environment.We analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic damage.We proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal pressures.The fragments of the catastrophically damaged COPVs were collected after the tests.The crack distribution and propagation process of the catastrophic ruptures of the COPVs were analyzed.Our findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs. 展开更多
关键词 Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms
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Dynamic Multi-Physics Behaviors and Performance Loss of Cylindrical Batteries Upon Low-Velocity Impact Loading
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作者 Qingdan Huang Yang Bai +2 位作者 Han Luo Yikai Jia Chao Zhang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期184-192,共9页
In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and... In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and explosion incidents.Consequently,it is imperative to investigate the safety performance of LIBs under mechanical loads.This study is grounded in a more realistic coupling scenario consisting of electrochemical cycling and low-velocity impact.We systematically and experimentally uncovered the mechanical,electrochemical,and thermal responses,damage behavior,and corresponding mechanisms under various conditions.Our study demonstrates that higher impact energy results in increased structural stiffness,maximum temperature,and maximum voltage drop.Furthermore,heightened impact energy significantly influences the electrical resistance parameters within the internal resistance.We also examined the effects of State of Charge(SOC)and C-rates.The methodology and experimental findings will offer insights for enhancing the safety design,conducting risk assessments,and enabling the cascading utilization of energy storage systems based on LIBs. 展开更多
关键词 cycling performance damaged battery lithium-ion battery low-velocity impact mechanical safety
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An impact sensitivity assessment method of spacecraft based on virtual exterior wall
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作者 Runqiang Chi Yuyan Liu +1 位作者 Diqi Hu Baojun Pang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期142-157,共16页
The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft... The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft.An impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational efficiency.This method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays,which are assumed to originate from a non-concave virtual wall that completely wraps the spacecraft.The Dist Mesh method was adopted for the generating of the virtual wall to ensure its mesh quality.The influences of the sizes,mesh densities,shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and spacecraft.The results of this method were compared with those of S3DE(Survivability of Spacecraft in Space Debris Environment),BUMPER,MDPANTO,ESABASE2/Debris to verify the feasibility of the method.The PCHIP(Piecewise Cubic Hermite Interpolating Polynomial)was used to fit the size vs.flux relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft. 展开更多
关键词 Sensitivity OD/M SPACECRAFT Virtual exterior wall
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Economic significance and environmental impacts of the Song Dam Drinking Water Project(SDDWP)in Garhwal Himalaya
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作者 Vishwambhar Prasad SATI 《Regional Sustainability》 2024年第2期140-152,共13页
With the population growth through natural growth and migration,coupled with the city expansion,it is the fact that Dehradun City in India faces severe water scarcity.Therefore,the Song Dam Drinking Water Project(SDDW... With the population growth through natural growth and migration,coupled with the city expansion,it is the fact that Dehradun City in India faces severe water scarcity.Therefore,the Song Dam Drinking Water Project(SDDWP)is proposed to provide ample drinking water to Dehradun City and its suburban areas.This paper examined economic significance and environmental impacts of the SDDWP in Garhwal Himalaya,India.To conduct this study,we collected data from both primary and secondary sources.There are 12 villages and 3 forest divisions in the surrounding areas of the proposed dam project,of which 3 villages will be fully submerged and 50 households will be affected.For this study,50 heads of the households were interviewed in the 3 submerged villages.The questions mainly focused on economic significance,environmental impacts,and rehabilitation issues of the dam project.The findings of this study indicate that economic significance of the dam project is substantial,including providing ample water for drinking and irrigation,contributing to groundwater recharge,creating job opportunities,and promoting the development of tourism and fisheries in the Doon Valley.In terms of the rehabilitation of the affected people,there are only 50 households in need of rehabilitation.Currently,the arable land of these affected people is not sufficient to sustain their livelihoods.The entire landscape is fragile,rugged,and precipitous;therefore,the affected people are willing to rehabilitate to more suitable areas in the Doon Valley.Moreover,it is essential to provide them with sufficient compensation packages including the compensation of arable land,houses,cash,common property resources,institutions,belongingness,and cultural adaptation.On the other hand,the proposed dam project will have adverse environmental impacts including arable land degradation,forest degradation,loss of fauna and flora,soil erosion,landslides,and soil siltation.These impacts will lead to the ecological imbalances in both upstream and downstream areas.This study suggests that the affected people should be given sufficient compensation packages in all respects.Afforestation programs can be launched in the degraded areas to compensate for the loss of forest in the affected areas. 展开更多
关键词 Water scarcity Rehabilitation issues Song Dam Drinking Water Project(SDDWP) Dehradun City Song River BASIN
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Protective performance of shear stiffening gel-modified foam against ballistic impact:Experimental and numerical study
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作者 Huan Tu Haowei Yang +9 位作者 Pengzhao Xu Zhe Yang Fan Tang Cheng Dong Yuchao Chen Lei Ren Wenjian Cao Chenguang Huang Yacong Guo Yanpeng Wei 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期510-520,共11页
As one of the most widely used personal protective equipment(PPE),body armors play an important role in protecting the human body from the high-velocity impact of bullets or projectiles.The body torso and critical org... As one of the most widely used personal protective equipment(PPE),body armors play an important role in protecting the human body from the high-velocity impact of bullets or projectiles.The body torso and critical organs of the wear may suffer severe behind-armor blunt trauma(BABT)even though the impactor is stopped by the body armor.A type of novel composite material through incorporating shear stiffening gel(STG)into ethylene-vinyl acetate(EVA)foam is developed and used as buffer layers to reduce BABT.In this paper,the protective performance of body armors composed of fabric bulletproof layers and a buffer layer made of foam material is investigated both experimentally and numerically.The effectiveness of STG-modified EVA in damage relief is verified by ballistic tests.In parallel with the experimental study,numerical simulations are conducted by LS-DYNA®to investigate the dynamic response of each component and capture the key mechanical parameters,which are hardly obtained from field tests.To fully describe the material behavior under the transient impact,the selected constitutive models take the failure and strain rate effect into consideration.A good agreement between the experimental observations and numerical results is achieved to prove the validity of the modelling method.The tests and simulations show that the impact-induced deformation on the human body is significantly reduced by using STG-modified EVA as the buffering material.The improvement of protective performance is attributed to better dynamic properties and more outstanding energy absorption capability of the composite foam. 展开更多
关键词 Ballistic behavior Composite foam Shear stiffening gel Finite element analysis Protective mechanism
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Predicting the electromechanical properties of small caliber projectile impact igniter using PZT dynamic damage constitutive model considering crack propagation 被引量:1
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作者 Rui-zhi Wang Zhi-qiang Wang +5 位作者 En-ling Tang Lei Li Guo-lai Yang Chun Cheng Li-ping He Ya-fei Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第10期121-135,共15页
Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initi... Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initiation,propagation and crushing.At present,the electrical output performance of PZTs in projectile is usually calculated by quasi-static piezoelectric equation without considering the dynamic effect caused by strong impact and the influence of crack propagation on material properties.So the ignition parameters are always not accurately predicted.To tackle this,a PZT dynamic damage constitutive model considering crack propagation is established based on the dynamic impact test and the crack propagation theory of brittle materials.The model is then embedded into the ABAQUS subroutine and used to simulate the electromechanical response of the impact igniter during the impact of a small caliber projectile on the target.Meanwhile,the experiments of projectile with impact igniter impact on the target are carried out.The comparison between experimental and numerical simulation results show that the established dynamic damage model can effectively predict the dynamic electromechanical response of PZTs in the missile service environment. 展开更多
关键词 Piezoelectric ceramics IMPACT IGNITER Dynamic damage constitutive model Electromechanical response
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Climate Change Perceptions , Impacts and Adaptation Strategies of F arm Households in Potohar Region of Punjab, Pakistan
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作者 Sohaib Aqib Syed Mohsin Ali Kazmi +2 位作者 Muhammad Amjad Ahmed Ali Soomro Ghulam Farooque Khoso 《Journal of Energy and Power Engineering》 CAS 2023年第4期136-151,共16页
Climate change has become a global phenomenon and is adversely affecting agricultural development across the globe.Developing countries like Pakistan where 18.9%of the GDP(gross domestic product)came from the agricult... Climate change has become a global phenomenon and is adversely affecting agricultural development across the globe.Developing countries like Pakistan where 18.9%of the GDP(gross domestic product)came from the agriculture sector and also 42%of the labor force involved in agriculture.They are directly and indirectly affected by climate change due to an increase in the frequency and intensity of climatic extreme events such as floods,droughts and extreme weather events.In this paper,we have focused on the impact of climate change on farm households and their adaptation strategies to cope up the climatic extremes.For this purpose,we have selected farm households by using multistage stratified random sampling from four districts of the Potohar region i.e.Attock,Rawalpindi,Jhelum and Chakwal.These districts were selected by dividing the Potohar region into rain-fed areas.We have employed logistic regression to assess the determinants of adaptation to climate change and its impact.We have also calculated the marginal effect of each independent variable of the logistic regression to measure the immediate rate of change in the model.In order to check the significance of our suggested model,we have used hypothesis testing. 展开更多
关键词 Climate change multistage stratified random sampling IMPACTS adaptation strategies logistic regression marginal effect Hypothesis testing
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Extended Impact of Cold Air Invasions in East Asia in Response to a Warm South China Sea and Philippine Sea
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作者 Marco Y.-T.LEUNG Dongxiao WANG +1 位作者 Wen ZHOU Yuntao JIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第3期531-540,共10页
During boreal winter,the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts.Here,we find that the intensity of strong synoptic cold days in the... During boreal winter,the invasion of cold air can lead to remarkable temperature drops in East Asia which can result in serious socioeconomic impacts.Here,we find that the intensity of strong synoptic cold days in the East China Sea and Indochina Peninsula are increasing.The enhanced synoptic cold days in these two regions are attributed to surface warming over the South China Sea and Philippine Sea(SCSPS).The oceanic forcing of the SCSPS on the synoptic cold days in the two regions is verified by numerical simulation.The warming of the SCSPS enhances the baroclinicity,which intensifies meridional wind and cold advection on synoptic timescales.This leads to a more extended region that is subject to the influence of cold invasion. 展开更多
关键词 ocean warming extra-tropical cyclones BAROCLINICITY temperature whiplash
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Survivability assessment of spacecraft impacted by orbit debris 被引量:2
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作者 Di-qi Hu Bao-jun Pang +2 位作者 Run-qiang Chi Zhang-chi Song Hao Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第3期961-970,共10页
To help optimize the spacecraft design and reduce the risk of spacecraft mission failure, a new approach to assess the survivability of spacecraft in orbit is presented here, including the following three steps: 1)Sen... To help optimize the spacecraft design and reduce the risk of spacecraft mission failure, a new approach to assess the survivability of spacecraft in orbit is presented here, including the following three steps: 1)Sensitivity Analysis of spacecraft. A new sensitivity analysis method, a ray method based on virtual outer wall, is presented here. Using rays to simulate the debris cloud can effectively address the component shadowing issues. 2) Component Vulnerability analysis of spacecraft. A function "Component functional reduction degree-Component physical damage degree" is provided here to clearly describe the component functional reduction. 3) System-level Survivability Assessment of spacecraft. A new method based on expert knowledge reasoning, instead of traditional artificial failure tree method, is presented here to greatly improve the efficiency and accuracy of calculation. 展开更多
关键词 SURVIVABILITY Hypervelocity impact Orbit debris Ray method
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Assessment of possible impacts of climate change on the hydrological regimes of different regions in China 被引量:1
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作者 Alfredo REDER Guido RIANNA +1 位作者 Renata VEZZOLI Paola MERCOGLIANO 《Advances in Climate Change Research》 SCIE CSCD 2016年第3期169-184,共16页
The aim of this work is to investigate the soil water budget across China by means of hydrological modeling under current and future climate conditions and to evaluate the sensitivity to soil parameters. For this purp... The aim of this work is to investigate the soil water budget across China by means of hydrological modeling under current and future climate conditions and to evaluate the sensitivity to soil parameters. For this purpose, observed precipitation and temperature data(1981-2010) and climate simulations(2021-2050, 2071-2100) at high resolution(about 14 km) on a large part of China are used as weather forcing. The simulated weather forcing has been bias corrected by means of the distribution derived quantile mapping method to eliminate the effects of systematic biases in current climate modeling on water cycle components. As hydrological models, two 1D models are tested: TERRA-ML and HELP. Concerning soil properties, two datasets, provided respectively by Food and Agriculture Organization and U.S. Department of Agriculture, are separately tested. The combination of two hydrological models, two soil parameter datasets and three weather forcing inputs(observations, raw and bias corrected climate simulations) results in ?ve different simulation chains.The study highlights how the choice of some approaches or soil parameterizations can affect the results both in absolute and in relative terms and how these differences could be highly related to weather forcing in inputs or investigated soil. The analyses point out a decrease in average water content in the shallower part of the soil with different extents according to climate zone, concentration scenario and soil/cover features.Moreover, the projected increase in temperature and then in evapotranspirative demand do not ever result in higher actual evapotranspiration values, due to the concurrent variations in precipitation patterns. 展开更多
关键词 Water BALANCE models Model comparison BIAS correction HYDROLOGICAL IMPACTS Soil parameters China
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An investigation on anti-impact and penetration performance of basalt fiber composites with different weave and lay-up modes 被引量:1
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作者 Hai-dong Fu Xin-ya Feng +3 位作者 Jin-xu Liu Zhi-ming Yang Chuan He Shu-kui Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第4期787-801,共15页
The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and b... The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and ballistic test were performed to the prepared composites.After the tests,the specimens were recovered and analyzed for micromorphology.Three-point bending tests show that both the bending strength and stiffness of the WBFC surpass those of the UBFC.Low velocity impact test results show that the low velocity impact resistance to hemispherical impactor of the UBFC is higher than that of the WBFC,but the low velocity impact resistance to sharp impactor of the UBFC is lower than that of the WBFC.For the ballistic test,it can be found that the ballistic property of the UBFC is higher than that of the WBFC. After the tests,microscopic analysis of the specimens was applied,and their failure mechanism was discussed.The main failure modes of the UBFC are delamination and fibers breakage under the above loading conditions while the main failure mode of the WBFC is fibers breakage.Although delamination damage can be found in the WBFC under the above loading conditions,the degree of delamination is far less than that of the UBFC. 展开更多
关键词 The woven basalt fiber composites The[0°/90°/45°/-45°]_s basalt fiber COMPOSITES Low velocity impact Ballistic test DELAMINATION
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Effect of Fracture Criteria on Taylor Impact Fracture
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作者 Wei Zhang Gang Wei +1 位作者 Xin-Ke Xiao Zi-Tao Guo 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第1期63-67,共5页
Taylor impact test on aluminum alloy 7A04-T6 presented in a previous study has been numerically evaluated using the finite element code ABAQUS/Explicit in this paper. The influence of fracture criterion in numerical s... Taylor impact test on aluminum alloy 7A04-T6 presented in a previous study has been numerically evaluated using the finite element code ABAQUS/Explicit in this paper. The influence of fracture criterion in numerical simulations of the deformation and fracture behavior of Taylor rod has been studied. The following fracture criterions, included a modified version of Johnson-Cook, the Cockcroft-Latham(C-L), the constant fracture strain, the maximum shear stress and the maximum principle stress fracture models, have been used in this paper. Model constants for each criterion are calibrated from material tests. The modified version of Johnson-Cook fracture criterion with the stress triaxiality cut-off idea used can give good prediction to the Taylor impact fracture behavior. However, the C-L fracture criterion with only a constant required for calibrating by a simple test is found to give reasonable predictions. Unfortunately, the other three criteria are not able to repeat the experimentally obtained fracture behavior. The result indicates that the stress triaxiality cut-off idea is necessary to predict the Taylor impact fracture. 展开更多
关键词 Taylor impact FRACTURE FRAGMENTATION fracture criterion
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Ballistic impact response of resistance-spot-welded(RSW) double-layered plates for Q&P980 steel
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作者 Bo-han Ma Dong-fang Ma +2 位作者 Huan-ran Wang Da-nian Chen Feng-hua Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第6期1052-1064,共13页
Ballistic impact response of resistance-spot-welded(RSW)double-layered(2×1.6 mm)plates(190 mm×150 mm)for Q&P980 steel impacted by a round-nosed steel bullet(12 mm diameter and 30 mm length)was investigat... Ballistic impact response of resistance-spot-welded(RSW)double-layered(2×1.6 mm)plates(190 mm×150 mm)for Q&P980 steel impacted by a round-nosed steel bullet(12 mm diameter and 30 mm length)was investigated by using gas gun and high-speed camera system.The RSW specimens were spot welded using a 6 mm diameter electrode face producing a 7.2 mm diameter fusion zone of the spot weld.The ballistic curve and energy balance for the tests of the spot weld of the RSW specimens at different velocity were analyzed to characterize the ballistic behavior of the RSW specimens under bullet impact.The fracture mechanisms of the RSW specimens under bullet impact were presented.For the tests below the ballistic limit,the cracks initiated from the notch-tip and propagated along the faying surface or obliquely through the thickness depending on the impact velocity.For the tests above the ballistic limit,the plug fracture in the front plate of the RSW specimen could be caused by the thinning-induced necking in the BM near the HAZ,while the plug fracture in the rear plate of the RSW specimens may be consist of the circumferential cracking from the rear surface and the bending fracture of the hinged part of material.The effects of the electrode indentation and the weld interfaces on deformation and fracture of the RSW specimens under bullet impact were revealed.For the tests above the ballistic limit,the circumferential fracture from the rear surface of the RSW specimens was always initiated along the interior periphery of the electrode indentation and the crack paths were along the FZ/CGHAZ or CGHAZ/FGHAZ interface.When the circumferential crack also formed outside the electrode indentation,the fracture on the BM/HAZ interface could be found.On the front plate of the RSW specimens,the shear/bending induced cracking from the notch-tip were observed and the crack paths were along the FZ/CGHAZ or CGHAZ/FGHAZ interface. 展开更多
关键词 RSW Q&P980 steel Ballistic impact Deformation Fracture
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Dynamic Fracture of Ti-5553 Alloy in Taylor Impact Test
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作者 Denghui Zhao Qian Wang +1 位作者 Lin Wang Maosheng Zhi 《Journal of Beijing Institute of Technology》 EI CAS 2017年第1期135-142,共8页
The dynamic fracture behavior of a new near-beta Ti-5Al-5Mo-5V-3Cr-1Fe(Ti-5553)alloy under a high strain rate loading was investigated systemically using the Taylor impact test,over the impact velocity ranging from1... The dynamic fracture behavior of a new near-beta Ti-5Al-5Mo-5V-3Cr-1Fe(Ti-5553)alloy under a high strain rate loading was investigated systemically using the Taylor impact test,over the impact velocity ranging from156 ms-1 to 256 ms-1.An optical microscope(OM)and a scanning electron microscope(SEM)were used to characterize the microstructure evolution.The experimental results have demonstrated that the velocity from deformation to fracture is 256 ms-1 for the alloy with anα+βduplex microstructure including more primaryαphase,while the velocity is 234 ms-1 for the alloy with a duplex microstructure including less primaryα phase.From the impact fracture morphologies,smooth and smeared surfaces and ductile dimple areas can be observed.The failure mode of the titanium alloy with both microstructures is adiabatic shear banding.According to the fracture analysis,the ductile fracture area with the dimple area in the alloy with much more primaryαphase were more than that with less primaryαphase.Compared to the duplex microstructure with less primaryα phase,Ti-5553 alloy with more primaryαphase exhibited a better capability to resist an adiabatic shear damage. 展开更多
关键词 Ti-5Al-5Mo-5V-3Cr-IFe Taylor impact test dynamic fracture behavior adiabatic shearband
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The Impact of Soil Moisture on Dispersion-Related Characteristics
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作者 贾新媛 叶卓佳 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1990年第4期441-452,共12页
This study investigates the impact of soil moisture availability on dispersion-related characteristics: surface friction velocity (u* ), characteristic scales of temperature and humidity (T * and q * ), the planetary ... This study investigates the impact of soil moisture availability on dispersion-related characteristics: surface friction velocity (u* ), characteristic scales of temperature and humidity (T * and q * ), the planetary boundary layer height (h) and atmospheric stability classified by Monin-Obukhov length (L), Kazanski-Monin parameter (μ) and convective velocity scale (w* ) during daytime convective condition using a one-dimensional primitive equation with a refined soil model. 展开更多
关键词 As The Impact of Soil Moisture on Dispersion-Related Characteristics
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The Impact of Soil Moisture Availability upon the Partition of Net Radiation into Sensible and Latent Heat Fluxes
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作者 叶卓佳 贾新媛 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第3期339-350,共12页
The impact of soil moisture availability on the Bowen ratio and on the partition of net radiation flux into sensible, latent and soil heat fluxes was investigated by using one-dimensional primitive equations with a re... The impact of soil moisture availability on the Bowen ratio and on the partition of net radiation flux into sensible, latent and soil heat fluxes was investigated by using one-dimensional primitive equations with a refined soil parameterization scheme. Simulation results presented that as soil moisture availability increases, the Bowen ratio and the partition of net radiation flux into sensible and soil heat fluxes decrease. The partition of net radiation flux into latent heat flux, however, increases. Quantitative relationships between Bowen ratio and the partitions with soil moisture availability were also given in this study. 展开更多
关键词 heat The Impact of Soil Moisture Availability upon the Partition of Net Radiation into Sensible and Latent Heat Fluxes
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Impact of the South China Sea Throughflow on the Pacific Low-Latitude Western Boundary Current:A Numerical Study for Seasonal and Interannual Time Scales 被引量:7
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作者 王伟文 王东晓 +3 位作者 周文 刘钦燕 俞永强 李超 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第6期1367-1376,共10页
Prior studies have revealed that,as a part of the Pacific tropical gyre,the South China Sea throughflow(SCSTF) is strongly influenced by the Pacific low-latitude western boundary current(LLWBC).In this study,ocean... Prior studies have revealed that,as a part of the Pacific tropical gyre,the South China Sea throughflow(SCSTF) is strongly influenced by the Pacific low-latitude western boundary current(LLWBC).In this study,ocean general circulation model(OGCM) experiments with and without connection to the South China Sea(SCS) were performed to investigate the impact of the SCSTF on the Pacific LLWBC.These model experiments show that if the SCS is blocked,seasonal variability of the Kuroshio and Mindanao Current becomes stronger,and the meridional migration of the North Equatorial Current(NEC) bifurcation latitude is enhanced.Both in seasonal and interannual time scales,stronger Luzon Strait transport(LST) induces a stronger Kuroshio transport combined with a southward shift of the NEC bifurcation,which is unfavorable for a further increase of the LST;a weaker LST induces a weaker Kuroshio transport and a northward shifting NEC bifurcation,which is also unfavorable for the continuous decrease of the LST. 展开更多
关键词 South China Sea throughflow low-latitude western boundary current KUROSHIO NEC bifurcation
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Post deformation analysis of the ballistic impacted magnesium alloys,a short-review 被引量:2
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作者 Abdul Malik Yangwei Wang +2 位作者 Cheng Huanwu Faisal Nazeer Muhammad Abubaker Khan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第5期1518-1535,共18页
From the mechanistic point of view,magnesium alloys are lightweight materials and are receiving increasing attention in the past several years in various fields.Prof.Liang Zhen from Harbin Institute of Technology,Chin... From the mechanistic point of view,magnesium alloys are lightweight materials and are receiving increasing attention in the past several years in various fields.Prof.Liang Zhen from Harbin Institute of Technology,China and the United State military are showing keen interest in the development of magnesium alloys as ballistic resistant material.However,their use is still limited owing to low ductility,low formability,and average mechanical properties.The magnesium alloys components must withstand the shockwave under hypervelocity ballistic impact.The ballistic testing can produce gradient variations of the strain and stress-energy away from the crater,and useful for the development of these alloys in the military and aerospace industry.Therefore,the present review article shed light on the post deformation analysis of the Mg alloys subjected to the different projectiles under ballistic impact,and the underlying mechanisms were discussed.In the end,some important issues regarding the ballistic impact and further studies in this field were proposed. 展开更多
关键词 Ballistic behavior Mg alloys Deformed zones TEXTURE HARDNESS
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Impacts of a wind stress and a buoyancy flux on the seasonal variation of mixing layer depth in the South China Sea 被引量:4
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作者 XIAO Xianjun WANG Dongxiao +4 位作者 ZHOU Wen ZHANG Zuqiang QIN Yinghao HE Na ZENG Lili 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2013年第9期30-37,共8页
The seasonal variation of mixing layer depth (MLD) in the ocean is determined by a wind stress and a buoy- ance flux. A South China Sea (SCS) ocean data assimilation system is used to analyze the seasonal cycle of... The seasonal variation of mixing layer depth (MLD) in the ocean is determined by a wind stress and a buoy- ance flux. A South China Sea (SCS) ocean data assimilation system is used to analyze the seasonal cycle of its MLD. It is found that the variability of MLD in the SCS is shallow in summer and deep in winter, as is the case in general. Owing to local atmosphere forcing and ocean dynamics, the seasonal variability shows a regional characteristic in the SCS. In the northern SCS, the MLD is shallow in summer and deep in winter, affected coherently by the wind stress and the buoyance flux. The variation of MLD in the west is close to that in the central SCS, influenced by the advection of strong western boundary currents. The eastern SCS presents an annual cycle, which is deep in summer and shallow in winter, primarily impacted by a heat flux on the air-sea interface. So regional characteristic needs to be cared in the analysis about the MLD of SCS. 展开更多
关键词 wind stress buoyance flux mixed layer South China Sea
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Impact of Crash Environments on Crashworthiness of Fuselage Section 被引量:2
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作者 TANG Huan ZHU Shuhua +1 位作者 LIU Xiaochuan XI Xulong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第S01期1-8,共8页
In order to study the crash resistance of the civil aircraft structure in different crash environments,two environmental models of soft soil and water are established to analyze the dynamic response of the fuselage se... In order to study the crash resistance of the civil aircraft structure in different crash environments,two environmental models of soft soil and water are established to analyze the dynamic response of the fuselage section subjected to the vertical at the impact velocity of 7 m/s.Simulation results show that the soft crash environment can have a certain cushioning effect on the structure crash,but it will prolong the crash time and change the energy absorption mode.This work suggests that soft environment may not be suitable for forced landing. 展开更多
关键词 CRASHWORTHINESS dynamic response fuselage section soft soil WATER
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