Analytical and Numerical Analysis on a New Type of Bolted Connection for Modular Steel Construction

En-Feng Deng,Jun-Yi Lian,Zhe Zhang,Zhe Liu,Ji-Jian Zhou,Shi-Quan Wang 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.4

Modular steel construction (MSC) has exhibited widespread applications in civil engineering. The inter-module connection is a key issue for the seismic performance of MSC. A detailed finite element model (FEM) of a new type of bolted connection was firstly developed. Its accuracy was validated by comparing numerical results with previous experimental results in terms of hysteretic curve and failure mode. A theoretical mechanical model was developed and its capabilities on predictions of initial rotational stiffness and ultimate moment resistance of the connection were checked through validations against test results. Further, a parametric study on several specimens with different axial load ratios, boundary conditions and section of the beams was conducted. The prediction capability of the theoretical model on seismic behavior of the connection with different beam sections was checked by comparing the skeleton curves of FEA results with theoretical ones. Subsequently, a simplified FEM was established and validated to accelerate the numerical simulation of the seismic performance of the connection.

A Novel Stability Criterion of Time-varying delay Fractional-order Financial Systems Based a New Functional Transformation Lemma

Zhe Zhang,Jing Zhang,Fanyong Cheng,Feng Liu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.4

This paper puts forward a novel stability criterion of all cases of the time-delay fractional-order financialsystems(FFS) including FFS without time delay, FFS with constant time delay and FFS with time-varying delay. This novel stability criterion is mainly based on a new stability judgment method which contains the deductionof Wirtinger inequality, Integral mean value theorem, fractional-order Lyapunov method, and a new functionaltransformation lemma which we deduced. This new functional transformation lemma simplifies the structure ofthe novel stability criterion with fewer constraints. Thus, compared with the previous stability criterion of FFS, thenovel stability criterion of FFS has clearer structure and lower conservatism. Moreover, the novel stability criterionof FFS can also satisfy all fractional-order operators from 0 to 1. Last but not least, some numerical simulationexamples are provided to verify the effectiveness and the benefit of the proposed novel stability criterion of FFS.

Multi-objective Global Optimization for Deformation Near a Hole in an Oxide Forming Alloy Foil Subjected to Thermal Cycling

Feng-Xun Li,Zhen-Zhe Li 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.2

The TBC (thermal barrier coating) systems provide protection against high temperature corrosion of the superalloy substrates in the gas turbine engines. However, the lateral growth of TGO (thermally-grown oxide) and the thermal expansion misfit between TGO and BC(bond coat) induce internal stress which can be sufficient to activate plastic deformation or buckling in TGO. In this paper, the analytic and optimization methods were applied for improving durability of the TBC system. First, an analytic method for obtaining the deformation results of TBC system was applied. In the following step, the analysis results were obtained for the experimental points selected by the D-optimal DOE method. Based on these analysis data, the fitting functions for showing the deformation of the TBC system were constructed using the response surface method. Finally, a multi-objective global optimization method was developed for upgrading durability of the TBC system. The developed analytic and optimization methods can be widely used to improve the performance of the TBC system for the gas turbine engines.

A novel transmissibility concept based on wavelet transform for structural damage detection

Zhe Fan,Xin Feng,Jing Zhou 국제구조공학회 2013 Smart Structures and Systems, An International Jou Vol.12 No.3

A novel concept of transmissibility based on a wavelet transform for structural damage detection is presented in this paper. The main objective of the research was the development of a method for detecting slight damage at the incipient stage. As a vibration-based approach, the concept of transmissibility has attracted considerable interest because of its advantages and effectiveness in damage detection. However, like other vibration-based methods, transmissibility-based approaches suffer from insensitivity to slight local damage because of the regularity of the traditional Fourier transform. Therefore, the powerful signal processing techniques must be found to solve this problem. Wavelet transform that is able to capture subtle information in measured signals has received extensive attention in the field of damage detection in recent decades. In this paper, we first propose a novel transmissibility concept based on the wavelet transform. Outlier analysis was adopted to construct a damage detection algorithm with wavelet-based transmissibility. The feasibility of the proposed method was numerically investigated with a typical six-degrees-of-freedom spring-mass system, and comparative investigations were performed with a conventional transmissibility approach. The results demonstrate that the proposed transmissibility is more sensitive than conventional transmissibility, and the former is a promising tool for structural damage detection at the incipient stage.

A Novel Stability Criteria of a Class Nonlinear Fractional-order HIV-1 System with Multiple Delay

Zhe Zhang,Jing Zhang,Fanyong Cheng,Feng Liu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

This paper mainly deduces a new stability criteria of the fractional-order HIV-1 system with delay on the basis of Wirtinger inequality, fractional-order Lyapunov method and integral mean value theorem. The Wirtinger inequality is rarely applied to stability analysis of fractional-order system. Nevertheless, this paper extends thegeneral form of the Lyapunov-krasovskii function to a novel fractional expression form by applying definitionof Caputo fractional derivative. Via the the integral mean value theorem, fractional-order Lyapunov method and Wirtinger inequality, the novel stability criteria is deduced. It is the integral mean value theorem that reduces the conservatism of the stability criteria. The simulation results show that the proposed criteria can satisfy different fractional-order operators.In addition, it can not only solve the stability problem of fractional-order HIV-1 system with the constant time delay, but also of the fractional-order HIV-1 system with time-varying time delay. Thus, the new stability criteria has generality and universality. So as to verify our theoretical results, many numerical simulations are provided.

Contribution Rate of Influent Factors Affecting Soil Moisture and its Scale Effect in Loess Plateau,China

Feng Jiao,Zhang Zhe,Ning-Xia Liang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

MicroRNA-100 Resensitizes Resistant Chondrosarcoma Cells to Cisplatin through Direct Targeting of mTOR

Zhu, Zhe,Wang, Cun-Ping,Zhang, Yin-Feng,Nie, Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Chondrosarcomas are malignant cartilage-forming tumors of bone which exhibit resistance to both chemotherapy and radiation treatment. miRNAs have been well demonstrated to regulate gene expression and play essential roles in a variety of biological processes, including proliferation, differentiation, migration, cell cycling and apoptosis. In this study, we obtained evidence that miR-100 acts as a tumor suppressor in human chondrosarcomas. Interestingly, cisplatin resistant chondrosarcoma cells exhibit decreased expression of miR-100 compared with parental cells. In addition, we identified mTOR as a direct target of miR-100. Overexpression of miR-100 complementary pairs to the 3' untranslated region (UTR) of mTOR, resulted in sensitization of cisplatin resistant cells to cisplatin. Moreover, recovery of the mTOR pathway by overexpression of S6K desensitized the chondrosarcoma cells to cisplatin, suggesting the miR-100-mediated sensitization to cisplatin dependent on inhibition of mTOR. In summary, the present studies highlight miR-100 as a tumor suppressor in chondrosarcoma contributing to anti-chemoresistance. Overexpression of miR-100 might be exploited as a therapeutic strategy along with cisplatin-based combined chemotherapy for the treatment of clinical chondrosarcoma patients.

Characterization of the Methylation Status of Pax7 and Myogenic Regulator Factors in Cell Myogenic Differentiation

Chao, Zhe,Zheng, Xin-Li,Sun, Rui-Ping,Liu, Hai-Long,Huang, Li-Li,Cao, Zong-Xi,Deng, Chang-Yan,Wang, Feng Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.7

Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.

A TEL decision method of process parameters for smart energy efficient manufacturing

Wei Zhe,Feng Yixiong,Hong Zhaoxi,Tan Jianrong 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.8

By constructing a Smart energy efficient manufacturing (SEEM) process grey model, craft parameter optimization is transformed into the process of multi-attribute decision making. Using fuzzy set theory to deal with uncertainty and inaccuracy fuzzy knowledge of SEEM assessment experts, a directly effect incidence matrix and a comprehensive effect matrix of SEEM process are put forward to be indexed by Trial and evaluation laboratory (TEL). The central degree and causal degree of each evaluation index are obtained, and then the relevance is analyzed between SEEM process evaluation indicators and weighted according to impact degrees. At the premise of maximizing of population benefits and minimizing of individual regret, the SEEM process parameters are determined by TEL-VIKOR theory. To obtain SEEM process parameters or compromise process parameters, a decision maker's subjective preference, and establishing control priorities of best SEEM process parameters are set. Finally, SEEM process parameters making decision example from discharge manufacturing process are applied to verify the proposed method.

A novel transmissibility concept based on wavelet transform for structural damage detection

Fan, Zhe,Feng, Xin,Zhou, Jing Techno-Press 2013 Smart Structures and Systems, An International Jou Vol.12 No.3

A novel concept of transmissibility based on a wavelet transform for structural damage detection is presented in this paper. The main objective of the research was the development of a method for detecting slight damage at the incipient stage. As a vibration-based approach, the concept of transmissibility has attracted considerable interest because of its advantages and effectiveness in damage detection. However, like other vibration-based methods, transmissibility-based approaches suffer from insensitivity to slight local damage because of the regularity of the traditional Fourier transform. Therefore, the powerful signal processing techniques must be found to solve this problem. Wavelet transform that is able to capture subtle information in measured signals has received extensive attention in the field of damage detection in recent decades. In this paper, we first propose a novel transmissibility concept based on the wavelet transform. Outlier analysis was adopted to construct a damage detection algorithm with wavelet-based transmissibility. The feasibility of the proposed method was numerically investigated with a typical six-degrees-of-freedom spring-mass system, and comparative investigations were performed with a conventional transmissibility approach. The results demonstrate that the proposed transmissibility is more sensitive than conventional transmissibility, and the former is a promising tool for structural damage detection at the incipient stage.