Dynamic behavior of SRC columns with built-in cross-shaped steels subjected to lateral impact

Yanhua Liu,Lei Zeng,Changjun Liu,Jinxu Mo,Buqing Chen 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.4

This paper presents an investigation on the dynamic behavior of SRC columns with built-in cross-shaped steels under impact load. Seven 1/2 scaled SRC specimens were subjected to low-speed impact by a gravity drop hammer test system. Three main parameters, including the lateral impact height, the axial compression ratios and the stirrup spacing, were considered in the response analysis of the specimens. The failure mode, deformation, the absorbed energy of columns, as well as impact loads are discussed. The results are mainly characterized by bending-shear failure, meanwhile specimens can maintain an acceptable integrity. More than 33% of the input impact energy is dissipated, which demonstrates its excellent impact resistance. As the impact height increases, the flexural cracks and shear cracks observed on the surface of specimens were denser and wider. The recorded time-history of impact force and mid-span displacement confirmed the three stages of relative movement between the hammer and the column. Additionally, the displacements had a notable delay compared to the rapid changes observed in the measured impact load. The deflection of the mid-span did not exceed 5.90mm while the impact load reached peak value. The impact resistance of the specimen can be improved by proper design for stirrup ratios and increasing the axial load. However, the cracking and spalling of the concrete cover at the impact point was obvious with the increasing in stiffness.

Experimental and Numerical Investigation on the Cyclic Behavior of SRC Columns considering Unsymmetrical Confinement Effect

Xianpan Liu,Lei Zeng,Yunfeng Xiao,Yanhua Liu,Heng Zhang,Yun Cao 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

Experimental and numerical studies were conducted on the cyclic behavior of steel reinforced concrete (SRC) columns with T-shaped and L-shaped steel section. A total of 8 SRC columns were tested under axial compression and lateral cyclic loading. The design details, loading procedure and main results, including the failure modes, hysteretic characteristics and ductility were reported. Four failure modes as flexural failure, shear bond failure, shear compression failure and shear compound failure were observed. By considering various unsymmetrical confinement and plastic hinge region, the experimental study was supplemented by numerical analysis to study the influence of axial compression ratio, shear-span ratio and concrete strength. The results revealed that the FEA is in good agreement with the experimental results. The ultimate loading of specimen with confinement effect has been improved by 21.4% − 33.8%. The failure modes is dominated by the shear-span ratio and type of cross section. The specimens with smaller shear-span ratio are prone to shear failure, while the unsymmetrical steel arrangement causes shear compound failure which is combined with shear bond failure and shear compression failure. Moreover, the specimens with larger shear-span ratio and stirrup ratio present greater deformation capacity and ductility. In practical engineering, the confinement degree of SRC columns with unsymmetrical steel section can be enhanced by increasing the stirrup ratio and arranging the cross ties.

Evaluation of Electrospinnability of Celluloses Derived from Different Biomass Resources

Yanhua Chen,Na Teng,Haizhen Chen,Jing Chen,Fei Liu,Haining Na,Jin Zhu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

Electrospinnability as well as dissolvability of the celluloses derived from different biomass resources are systematically studied in this work. By analyzing the essentially physical and molecular structure of cellulose in detail, dissolving efficiency and molecular chain entanglement in solution of cellulose are carefully realized. Accordingly, the original factors on electrospinnability of cellulose is revealed. Crystallinity mainly affects the dissolution of cellulose, which is the foundation to achieve electrospinning. Degree of polymerization is the decisive index of cellulose to form molecular entanglement in solution or not. Proper molecular entanglement of cellulose, just as corn cellulose II, could initiate the formation of ultrafine fiber with good morphology in electrospinning. Our research is no doubt helpful to establish a solid scientific and technical foundation for selection of cellulose to achieve high efficiency fabrication of ultrafine fiber in electrospinning.

Joint Optimization Method Combining Genetic Algorithm and Numerical Algorithm Based on MATLAB

Yanhua Guo,Feifei Liu,Ning Zhang,Tao Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.11

A two-bar plane truss is builtin MATLAB based on mathematical model. Then the authors use genetic algorithm toolbox to solve this problem. The parametric truss model is set up in the finite element analysis software ANSYS. It is analyzed by first-order algorithm. The comparison of two kinds results show the pure genetic algorithm doesn’t always have an advantage over other algorithms. In the end, a joint optimization method is put forward on the basis of genetic algorithm. It combines genetic algorithm based on MATLAB toolbox and numerical algorithm based on quasi-Newton method. This method is illustrated by the numerical example of the two-bar plane truss. The results show this joint optimization method can get the global optimal solution of this problem every time.

A characterization of parabola

Yanhua Yu,Huili Liu 대한수학회 2008 대한수학회보 Vol.45 No.4

In this paper, the parabola will be characterized as the plane curve whose curvature function and support function satisfy a condition, where we define the support function as the distance from origin to the tangent line. In this paper, the parabola will be characterized as the plane curve whose curvature function and support function satisfy a condition, where we define the support function as the distance from origin to the tangent line.

One-Pot Synthesis of α-Fe2O3 Nanospindles as High-Performance Lithium-Ion Battery Anodes

Yanhua Ding,Bing Liu,Rongsheng Cai,Tuo Xin,Chen Li,Linhua Xia,Yiqian Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.2

Hematite nanospindles with a uniform size of ~270 nm in length and ~90 nm in width are prepared using a facile one-step hydrothermal method. Polyvinylpyrrolidone (PVP) serves as a structure-directing agent to control the primary morphology and aggregations. When evaluated as anode materials for lithium-ion batteries (LIBs), the electrode of sodium alginate (SA) binder exhibits a much better electrochemical performance than that with the polyvinylidene fluoride (PVDF) binder. Remarkably, the electrode using SA binder can deliver a high reversible specific capacity of 979mAh · g -1 after 50 cycles and prominent rate capability. The microstructural evolution of the nanospindles after the electrochemical cycling is investigated by scanning transmission electron microscopy (STEM). Our results may provide important mechanistic insights for the design of nanostructured anode materials for LIBs.

Facile synthesis of imprinted submicroparticles blend polyvinylidene fluoride membranes at ambient temperature for selective adsorption of methyl p-hydroxybenzoate

Yanhua Cui,Minjia Meng,Dongshu Sun,Yan Liu,Jianming Pan,Xiaohui Dai,Yongsheng Yan 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.3

We developed a simple phase inversion technique to prepare molecularly imprinted membrane (MIM) at room temperature for membrane selective adsorption and separation of methyl p-hydroxybenzoate (M4HB). The prepared SMIP-MIM was characterized by SEM, FT-IR, TGA. Compared with non-imprinted membrane (NIM1-5) adsorbent, SMIP-MIM1-5 adsorbent with high specific surface area and showed higher binding capacity, faster kinetic and better selectively adsorption capacity for M4HB. The maximum isotherm adsorption capacity for M4HB of SMIPMIM4 was 3.519mg·g−1, and the experimental data was well fitted to the slips model by multiple analysis. The maximum kinetic adsorption capacity and equilibrium adsorption time for SMIP-MIM4 were 1.335mg·g−1 and 160 min, respectively. The mechanism for dynamic adsorption of M4HB onto SMIP-MIM4 was found to follow pseudo-firstorder model and pseudo-second-order model. Additionally, the permeability separation factor of SMIP-MIM4 for M4HB compared to a structural analogues methyl 2-hydroxybenzoate (M2HB) could reach 2.847. The adsorption capacity of SMIP-MIM4 for M4HB and M2HB was 0.549mg·cm−2 and 1.563mg·cm−2, respectively. The adsorption behavior of M4HB through SMIP-MIM4 followed the retarded permeation mechanism.

Bacillus ciccensis sp. nov., isolated from maize (Zea mays L.) seeds

Liu, Yang,Li, Nannan,Eom, Mi Kyung,Schumann, Peter,Zhang, Xin,Cao, Yanhua,Ge, Yuanyuan,Xiao, Ming,Zhao, Jiuran,Cheng, Chi,Kim, Song-Gun Microbiology Society 2017 International journal of systematic and evolutiona Vol.67 No.11

Research of Road Pricing System Based on P System

Yanhua Zhong,Wei Wei,Zhiyong Liu 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.6

For urban traffic congestion problem, a communication P systems using parallel computing principles congested road-use pricing model, considering congestion charges in the case, the establishment of travelers travel decision algorithm, travelers dynamic evolution in traffic P system, External charging parameters can be adjusted to influence traveler decisions, thereby affecting the whole system evolution. The congestion pricing model based on P system (CPS_ DTAM) of the simulation experiment shows that the algorithm is feasible. This model and particle swarm optimization congestion pricing model (PSO_ DTAM) were compared based on the same parameters; the results show that this pricing model taking into accounts the dynamic decision travelers more in line with the real situation.

Isolation and Characterization of a Putative Vacuolar Na+/H+ Antiporter Gene from Zoysia japonica L.

Yanhua Du,Qian Hei,Yaxin Liu,Hui Zhang,Kai Xu,Tao Xia 한국식물학회 2010 Journal of Plant Biology Vol.52 No.4

A Na+/H+ antiporter gene from Zoysia japonica (ZjNHX1) which is a member of plant NHX-genes family was cloned by reverse-transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE)technology. The isolated cDNA is 2,421 bp in length and contains one open-reading frame (ORF) which comprises 540amino acid residues and shows higher homology with other plant Na+/H+ antiporters. ZjNHX1 could partially complement the salt-sensitive phenotypes of Δnhx1 and Δena1-4Δnhx1 yeast mutants in the presence of NaCl, KCl, and LiCl. The expression of ZjNHX1 in Z. japonica increased after NaCl treatment and this result accords with that of Na+contents determination under the same treatment. These results implied that ZjNHX1 functions as a vacuolar Na+/H+antiporter and plays an important role in salt tolerance and ion homeostasis in Z. japonica.