Transient analysis of layered beams subjected to steady heat supply and mechanical load

Zhong Zhang,Ding Zhou,Jiandong Zhang,Hai Fang,Huixuan Han 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.1

In this study, an analytical model is developed for the analysis of transient temperature, displacements, and stresses in simply supported layered beams. The beam is suddenly heated from the top and bottom surfaces by external steady heat sources and is subjected to a mechanical load. The temperature in each layer is variable along the thickness and follows the one-dimensional (1-D) transient heat transfer equation. The Laplace transform approach is used to obtain the transient temperature field in the beam. The thermoelastic constants of the beam are temperature-dependent. Dividing every layer into a series of thin slices, the temperature and the thermoelastic constants for each slice can be considered uniform. The two-dimensional (2-D) thermoelasticity theory is adopted to derive the governing equations of displacements and stresses in each slice. The transfer matrix method is applied to obtain the displacement and stress solutions for the beam. As an example, the distributions of transient temperature, displacements, and stresses in a three-layer beam are studied. The effects of the temperature dependent thermoelastic constants on the mechanical behavior of the beam are discussed in detail.

The Use of GA and PSO in Evaluating the Shear Strength of Steel Fiber Reinforced Concrete Beams

Jiandong Huang,Mengmeng Zhou,Jia Zhang,Jiaolong Ren,Nikolai Ivanovich Vatin,Mohanad Muayad Sabri Sabri 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.9

Shear failure in concrete specimens and beams is one of the most sensitive cases in construction projects. Since the shear strength of specimens is affected by various parameters, it is important to study them to arrive at a predictive relationship or model. This research has used the computational methods of machine learning to achieve a new evaluation of the shear strength of reinforced concrete (RC) beams. In the first step, 85 laboratory samples were examined. These samples had different geometric and non-geometric properties. The effect of each parameter was examined for smart models, then the optimal state of the parameters was determined. By optimizing the number of parameters, basic models were developed. The different structures of these models were investigated for the accurate evaluation of the shear strength of the samples. Finally, in the second step, the particle swarm optimization (PSO) and genetic algorithm (GA) were used to perpetuate and optimize the weights of the base models. The hybrid models were developed and applied with different structures for evaluation of shear strength and the best models were selected from them. The results showed that both models offer better performance than the base model. However, the GA-based model achieved higher accuracy and less error than the PSO-based model. Finally, the performance of these models was used for new data to evaluate their performance. As the main achievement of this research, these methods can be recommended and implemented for other conditions as well.

RFID Bi-Directional Authentication Protocol Based on Dynamic Coupled Integer Tent Map

Liu Jiandong,Zhang Xiao,Wang Yequan,Shang Kai 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.3

To meet the special needs of RFID, it is proposed to use a coupled dynamic integer tent map lattices model (DCML) to implement a Hash function and a random number generation scheme. The scheme is featured with fast operation. Based on this, this paper proposes RFID bi-directional authentication protocol. This has strictly proved by BAN logic. This protocol can resolve eavesdropping, illegal access, location tracking, impersonation and replay attack.

Soil Salinity Variability and its Driving Factors at Multiple Spatio-Temporal Scales in the Oasis Of Xinjiang, China

Wentai Zhang,Hongqi Wu,Haibin Gu,Ze Wang,Jiandong Sheng 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Soil Water Erosion and Conservation in Xinjiang, the Most Arid Region of China

Wentai Zhang,Haibin Gu,Jiandong Sheng 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Discrete Terminal Integral Sliding-Mode Backstepping Speed Control of SMPMSM Drives Based on Ultra-Local Mode

Huang Jiandong,Li Hongmei,Yang Liguo,Zhao Haonan,Zhang Peng 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4

In this paper, a novel discrete terminal integral sliding-mode backstepping control (DTISM-BSC) is proposed for the surface-mounted permanent magnet synchronous motor (SMPMSM) drive system, which improves the speed tracking performance and robustness of the system. In this control scheme, the discrete ultra-local model (ULM) of the SMPMSM drives, which employs the algebraic parameter identification technology to handle the unknown disturbance and parametric uncertainties, is first set up. Then, the terminal integral sliding-mode surface is proposed for its advantages of finite-time convergence to achieve speed rapid tracking, in which the control performance of backstepping control is improved. Thirdly, the equivalent control law is combined with the designed switching law to construct the speed controller based on the ULM. In this case, the bounded function is adopted to improve chattering problem. Meanwhile, the asymptotic stability and rapid convergence is verified. Finally, the experimental comparisons between the proposed method and the non-singular terminal sliding mode backstepping control (NTSM-BSC) are developed to validate the effectiveness of the proposed DTISM-BSC.

In vitro Degradation and Protein Release of Transparent and Opaque Physical Hydrogels of Block Copolymers at Body Temperature

Lin Yu,Jiandong Ding,Zheng Zhang 한국고분자학회 2012 Macromolecular Research Vol.20 No.3

Poly(D,L-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(D,L-lactide-co-glycolide) (PLGA-PEGPLGA)triblock copolymers were synthesized at 130 and 160 oC. The concentrated aqueous solutions of both specimens underwent reversible sol-to-(transparent gel)-to-(opaque gel) transitions upon heating but exhibited different critical gelation concentrations and transition temperatures, possibly due to the minor sequence differences between D,L-lactide (LA) and glycolide (GA) in the PLGA blocks. Aqueous solutions (20 wt%) of the copolymers synthesized at 130 and 160 oC spontaneously formed an opaque gel and a transparent gel at body temperature, respectively. The resulting hydrogels displayed similar in vitro degradation profiles in phosphate buffer saline solutions at 37 oC. Nevertheless, the late-stage releases of bovine serum albumin from the physical hydrogels differed. The present study reveals for the first time that transparent vs. opaque thermogel state influences some of their biomaterialrelated properties via the “overheat degree” of the thermogelling systems at a given working temperature, usually 37 oC.

Analysis of the Influence of Guide Vane Wrap Angle and Number of Blades on the Propulsion Performance of a Water-Jet Propeller

Wei Han,JianDong Mi,SiCong Zhang,Jun Xu,BinYu Qin 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.4

For water-jet propellers, the geometry size of the guide vane change can effectively improve the performance of the pump. If other parameters remain unchanged, CFD numerical simulation of the guide vane number and wrap angle of the change can be used to effectively adjust the operation conditions of the pump. The relationship between the changes in pump head, pump efficiency, and water-jet propeller propulsive efficiency can be used, to find the best guide vane parameters to achieve the highest thrust efficiency. The calculation results show that an increase in the guide vane number coefficient and wrap angle coefficient will reduce size of the pump head. Meanwhile, an increase in the wrap angle coefficient and the guide vane number coefficient will reduce the propulsive efficiency of the whole water-jet propeller. In this experiment, it was found that the propulsion effect is best when the guide vane number coefficient remains unchanged and the wrap angle coefficient is 1.

Genome-wide identification and comparative analysis of Alfin-like transcription factors in maize

Wei Zhou,Jiandong Wu,Qianqian Zheng,Yingli Jiang,Min Zhang,Suwen Zhu 한국유전학회 2017 Genes & Genomics Vol.39 No.3

Members of the Alfin-like (AL) transcription factor family, which contain a highly conserved DUF3594 domain and a PHD-finger motif, play important roles in the responses of plants to abiotic stress during various metabolic and physiological processes. To date, no systematic, comprehensive study of this family has been reported in maize. In this study, we identified 18 nonredundant ZmAL genes and classified them into four groups. These genes are unevenly distributed among all ten maize chromosomes except chromosome 9. Our results suggest that segmental duplication has played an important role in the expansion of the AL family in maize. Ka/Ks ratio analysis showed that most duplicated ZmALs have undergone large-scale purifying selection in the maize genome. We detected interspecies microsynteny among three graminaceous species, suggesting that there were independent duplication events in addition to the whole-genome duplication of the maize genome. Furthermore, microarray analysis showed that most ZmALs are differentially expressed in diverse tissues and stages. We also performed expression profiling of the ZmALs under salt, cold and drought stress conditions using quantitative reverse-transcription PCR (qRT-PCR). The results of this study provide useful clues for further functional analysis of the AL gene family in maize.

A discrete material optimization method with a patch strategy based on stiffness matrix interpolation

Pengwen Sun,Jie Zhang,Penghui Wu,Jiandong Li,Lanting Zhang,Weifei Hu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

A discrete material optimization method with a patch strategy based on the stiffness matrix interpolation is proposed, and a comprehensive technical process of patch discrete material optimization using existing finite element software was developed. This method employs the stiffness matrix instead of the constitutive matrix for material interpolation, which facilitates the optimization process integrated with the existing finite element software. The element stiffness matrix can be derived directly from the finite element analysis, which can not only ensure the correctness of the data, but also reduce the programming work of solving the numerical integration of the composite constitutive matrix. The mathematical model of the patch discrete material optimization is established, which takes the artificial density as the design variable, the minimum compliance as the objective function, and the sequential quadratic programming (SQP) algorithm as the optimization solver. Numerical examples show that by seeking a balance between the number of regions and practical production, the performance of the composite could be further improved using the discrete material optimization method with a patch strategy. Besides, the convergence rate of the optimization is increased by introducing the sum constraints of the design variables and the value functions. The effectiveness and the feasibility of the method were verified.