This paper focuses on the interface failure in metal/GFRP laminates on account of the high-velocity impact phenomenon by a hemispherical projectile.The study considers three laminates in which the failure inside the 8...This paper focuses on the interface failure in metal/GFRP laminates on account of the high-velocity impact phenomenon by a hemispherical projectile.The study considers three laminates in which the failure inside the 8-layer 0/90 GFRP laminate is compared with the other two laminates that include metal layers in their layup configuration.The metal layers were placed on the top and bottom on one type of laminates while in the other additional metal layers are placed symmetrically inside the layup as well.They were subjected to high-velocity impact by a hemispherical projectile at different energy levels and the idea is not to perforate the laminate configuration instead to account for the damage incurred in these laminates and the role of metal layers in providing resistance to damage within these laminates.The study utilizes experimental findings and proposes a rate-dependent Finite Element(FE)model consisting of the Hashin-Puck failure scheme for composite and the Johnson-Cook damage model for metal layers.The results of the model satisfactorily agree with their experimental counterparts and provide valuable insight into the damage resistance inside the laminates.It has been observed that the 8-layer GFRP laminate was good in terms of elastic recovery and prevention of propagation of damage inside the laminates only,till the impact energy was lower.For higher impact energy,they show poor damage resistance as the fiber failure is triggered in them.However,laminates with metal layers are shown to protect the laminate by dissipating energy in the delamination of metal/GFRP interface,shear failure of the metal layer,and on account of metal plasticity.The study further shows that the throughthickness compressive stresses were responsible for the failure of laminates and also triggering the delamination in them.A damage energy study was performed to investigate the amount of energy dissipating in various failure modes like delamination,matrix cracking,fiber failure,etc。展开更多
Cardiotocography measures the fetal heart rate in the fetus during pregnancy to ensure physical health because cardiotocography gives data about fetal heart rate and uterine shrinkages which is very beneficial to dete...Cardiotocography measures the fetal heart rate in the fetus during pregnancy to ensure physical health because cardiotocography gives data about fetal heart rate and uterine shrinkages which is very beneficial to detect whether the fetus is normal or suspect or pathologic.Various cardiotocography measures infer wrongly and give wrong predictions because of human error.The traditional way of reading the cardiotocography measures is the time taken and belongs to numerous human errors as well.Fetal condition is very important to measure at numerous stages and give proper medications to the fetus for its well-being.In the current period Machine learning(ML)is a well-known classification strategy used in the biomedical field on various issues because ML is very fast and gives appropriate results that are better than traditional results.ML techniques play a pivotal role in detecting fetal disease in its early stages.This research article uses Federated machine learning(FML)and ML techniques to classify the condition of the fetus.This study proposed a model for the detection of bio-signal cardiotocography that uses FML and ML techniques to train and test the data.So,the proposed model of FML used numerous data preprocessing techniques to overcome data deficiency and achieves 99.06%and 0.94%of prediction accuracy and misprediction rate,respectively,and parallel the proposed model applying K-nearest neighbor(KNN)and achieves 82.93%and 17.07%of prediction accuracy and misprediction accuracy,respectively.So,by comparing both models FML outperformed the KNN technique and achieved the best and most appropriate prediction results as compared with previous studies the proposed study achieves the best and most accurate results.展开更多
纤维金属层板(Fiber Metal Laminates,FMLs)传统成形方法难以成形复杂曲面构件,限制了其在汽车行业的应用。为提高FMLs成形能力,提出了一种直接采用模具加热预堆叠层板的热态气胀成形方法。首先通过力学性能试验探究了热塑性FMLs中材料...纤维金属层板(Fiber Metal Laminates,FMLs)传统成形方法难以成形复杂曲面构件,限制了其在汽车行业的应用。为提高FMLs成形能力,提出了一种直接采用模具加热预堆叠层板的热态气胀成形方法。首先通过力学性能试验探究了热塑性FMLs中材料铺层参数对力学性能影响,随后结合试验和仿真探究了热态气胀成形方法制备FMLs曲率构件过程中工艺参数对成形效果的影响,研究显示纤维参数决定了FMLs损伤容限,PA6树脂基FMLs成形工艺温度窗口为230~250℃,成形所需最低压强为3 MPa。研究结果表明利用热态气胀成形方法可成功制备热塑性FMLs曲率构件,温度和压强是决定成形效果的关键因素。展开更多
In this paper, definition and properties of logistic map along with orbit and bifurcation diagrams, Lyapunov exponent, and its histogram are considered. In order to expand chaotic region of Logistic map and make it su...In this paper, definition and properties of logistic map along with orbit and bifurcation diagrams, Lyapunov exponent, and its histogram are considered. In order to expand chaotic region of Logistic map and make it suitable for cryptography, two modified versions of Logistic map are proposed. In the First Modification of Logistic map (FML), vertical symmetry and transformation to the right are used. In the Second Modification of Logistic (SML) map, vertical and horizontal symmetry and transformation to the right are used. Sensitivity of FML to initial condition is less and sensitivity of SML map to initial condition is more than the others. The total chaotic range of SML is more than others. Histograms of Logistic map and SML map are identical. Chaotic range of SML map is fivefold of chaotic range of Logistic map. This property gave more key space for cryptographic purposes.展开更多
High velocity ballistic impact deformation behaviour of Titanium/GFRP Fiber Metal Laminates(FML)has been explored.Both single and multiple projectiles impact conditions were considered.Ti/GFRP FML targets were fabrica...High velocity ballistic impact deformation behaviour of Titanium/GFRP Fiber Metal Laminates(FML)has been explored.Both single and multiple projectiles impact conditions were considered.Ti/GFRP FML targets were fabricated with addition of 5%and 10%weight percentage of boron carbide(B_(4)C)particles.Mechanical properties of Ti/GFRP FML targets were determined as per ASTM standards.High velocity ballistic experiments were conducted using Armour Piercing Projectile(APP)of diameter 7.62 mm and velocity ranging between 350 and 450 m/s.Depth of penetration of the projectile into the target was measured.The deformation behaviour of Ti/GFRP targets with and without the presence of ceramic powder(B_(4)C)was investigated.“Ductile hole growth”failure mode was observed for pure GFRP target when subjected to single projectile impact whereas“plugging”failure mode was noted for Ti/GFRP targets.The presence of B_(4)C(5%by weight)particles has significantly improved the ballistic resistance of the Ti/GFRP FML target by offering frictional resistance to the projectile penetration.Further addition(10%by weight)of B_(4)C has reduced the ballistic performance due to agglomeration.None of the targets showed‘brittle cracking’or‘fragmentation’failures.When compared to the published results of Aluminium(Al 1100/GFRP and Al 6061/GFRP)FMLs,Ti/GFRP FML showed lesser DoP which increases its potential application to aerospace industry.展开更多
文摘This paper focuses on the interface failure in metal/GFRP laminates on account of the high-velocity impact phenomenon by a hemispherical projectile.The study considers three laminates in which the failure inside the 8-layer 0/90 GFRP laminate is compared with the other two laminates that include metal layers in their layup configuration.The metal layers were placed on the top and bottom on one type of laminates while in the other additional metal layers are placed symmetrically inside the layup as well.They were subjected to high-velocity impact by a hemispherical projectile at different energy levels and the idea is not to perforate the laminate configuration instead to account for the damage incurred in these laminates and the role of metal layers in providing resistance to damage within these laminates.The study utilizes experimental findings and proposes a rate-dependent Finite Element(FE)model consisting of the Hashin-Puck failure scheme for composite and the Johnson-Cook damage model for metal layers.The results of the model satisfactorily agree with their experimental counterparts and provide valuable insight into the damage resistance inside the laminates.It has been observed that the 8-layer GFRP laminate was good in terms of elastic recovery and prevention of propagation of damage inside the laminates only,till the impact energy was lower.For higher impact energy,they show poor damage resistance as the fiber failure is triggered in them.However,laminates with metal layers are shown to protect the laminate by dissipating energy in the delamination of metal/GFRP interface,shear failure of the metal layer,and on account of metal plasticity.The study further shows that the throughthickness compressive stresses were responsible for the failure of laminates and also triggering the delamination in them.A damage energy study was performed to investigate the amount of energy dissipating in various failure modes like delamination,matrix cracking,fiber failure,etc。
文摘Cardiotocography measures the fetal heart rate in the fetus during pregnancy to ensure physical health because cardiotocography gives data about fetal heart rate and uterine shrinkages which is very beneficial to detect whether the fetus is normal or suspect or pathologic.Various cardiotocography measures infer wrongly and give wrong predictions because of human error.The traditional way of reading the cardiotocography measures is the time taken and belongs to numerous human errors as well.Fetal condition is very important to measure at numerous stages and give proper medications to the fetus for its well-being.In the current period Machine learning(ML)is a well-known classification strategy used in the biomedical field on various issues because ML is very fast and gives appropriate results that are better than traditional results.ML techniques play a pivotal role in detecting fetal disease in its early stages.This research article uses Federated machine learning(FML)and ML techniques to classify the condition of the fetus.This study proposed a model for the detection of bio-signal cardiotocography that uses FML and ML techniques to train and test the data.So,the proposed model of FML used numerous data preprocessing techniques to overcome data deficiency and achieves 99.06%and 0.94%of prediction accuracy and misprediction rate,respectively,and parallel the proposed model applying K-nearest neighbor(KNN)and achieves 82.93%and 17.07%of prediction accuracy and misprediction accuracy,respectively.So,by comparing both models FML outperformed the KNN technique and achieved the best and most appropriate prediction results as compared with previous studies the proposed study achieves the best and most accurate results.
文摘纤维金属层板(Fiber Metal Laminates,FMLs)传统成形方法难以成形复杂曲面构件,限制了其在汽车行业的应用。为提高FMLs成形能力,提出了一种直接采用模具加热预堆叠层板的热态气胀成形方法。首先通过力学性能试验探究了热塑性FMLs中材料铺层参数对力学性能影响,随后结合试验和仿真探究了热态气胀成形方法制备FMLs曲率构件过程中工艺参数对成形效果的影响,研究显示纤维参数决定了FMLs损伤容限,PA6树脂基FMLs成形工艺温度窗口为230~250℃,成形所需最低压强为3 MPa。研究结果表明利用热态气胀成形方法可成功制备热塑性FMLs曲率构件,温度和压强是决定成形效果的关键因素。
文摘In this paper, definition and properties of logistic map along with orbit and bifurcation diagrams, Lyapunov exponent, and its histogram are considered. In order to expand chaotic region of Logistic map and make it suitable for cryptography, two modified versions of Logistic map are proposed. In the First Modification of Logistic map (FML), vertical symmetry and transformation to the right are used. In the Second Modification of Logistic (SML) map, vertical and horizontal symmetry and transformation to the right are used. Sensitivity of FML to initial condition is less and sensitivity of SML map to initial condition is more than the others. The total chaotic range of SML is more than others. Histograms of Logistic map and SML map are identical. Chaotic range of SML map is fivefold of chaotic range of Logistic map. This property gave more key space for cryptographic purposes.
基金the financial support received from the management of SSN。
文摘High velocity ballistic impact deformation behaviour of Titanium/GFRP Fiber Metal Laminates(FML)has been explored.Both single and multiple projectiles impact conditions were considered.Ti/GFRP FML targets were fabricated with addition of 5%and 10%weight percentage of boron carbide(B_(4)C)particles.Mechanical properties of Ti/GFRP FML targets were determined as per ASTM standards.High velocity ballistic experiments were conducted using Armour Piercing Projectile(APP)of diameter 7.62 mm and velocity ranging between 350 and 450 m/s.Depth of penetration of the projectile into the target was measured.The deformation behaviour of Ti/GFRP targets with and without the presence of ceramic powder(B_(4)C)was investigated.“Ductile hole growth”failure mode was observed for pure GFRP target when subjected to single projectile impact whereas“plugging”failure mode was noted for Ti/GFRP targets.The presence of B_(4)C(5%by weight)particles has significantly improved the ballistic resistance of the Ti/GFRP FML target by offering frictional resistance to the projectile penetration.Further addition(10%by weight)of B_(4)C has reduced the ballistic performance due to agglomeration.None of the targets showed‘brittle cracking’or‘fragmentation’failures.When compared to the published results of Aluminium(Al 1100/GFRP and Al 6061/GFRP)FMLs,Ti/GFRP FML showed lesser DoP which increases its potential application to aerospace industry.
