Daoming Shen¹, Hua Si^1,*, Jinhong Xia¹, Shunqun Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 63-76, 2019, DOI:10.32604/fdmp.2019.04799

Abstract The correct determination of thermal parameters, such as thermal conductivity and specific heat of soil during freezing, is the most important and basic problem for the construction of an appropriate freezing method. In this study, a calculation model of three stages of soil temperature was established. At the unfrozen and frozen stages, the specific temperatures of dry soil, water, and ice are known. According to the principle of superposition, a calculation model of unfrozen and frozen soils can be established. Informed by a laboratory experiment, the latent heat of the adjacent zone was calculated for the freezing stage based on… More >

Qiuren Ou^1,2,*, Peijun Ji², Jun Xiao¹, Ling Wu²

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 27-37, 2019, DOI:10.32604/fdmp.2019.04787

Abstract The properties of resin transfer molding (RTM) cyanate ester and its T800 grade carbon fiber composites were studied with the rheometer, differential scanning calorimetry (DSC), FT-IR, dynamic mechanical analyzer (DMA), thermal gravimetric analysis (TGA), mechanical property testing, and scanning electron microscopy (SEM). The results showed that the temperature of cyanate ester suitable for RTM process was 70℃. Curing process of the resin was 130℃/2 h+160℃/2 h+200℃/2 h+220℃/4 h. Glass transition temperature and heat decomposition temperature of the cured resin are 289℃ and 415℃, respectively. Mechanical properties of T800/RTM cyanate composites are 13.5% higher than that of T700/RTM cyanate composites and… More >

Wentao Ma¹, Jiaohua Qin^1,*, Xuyu Xiang¹, Yun Tan¹, Yuanjing Luo¹, Neal N. Xiong²

CMC-Computers, Materials & Continua, Vol.58, No.3, pp. 665-677, 2019, DOI:10.32604/cmc.2019.05683

Abstract As the first barrier to protect cyberspace, the CAPTCHA has made significant contributions to maintaining Internet security and preventing malicious attacks. By researching the CAPTCHA, we can find its vulnerability and improve the security of CAPTCHA. Recently, many studies have shown that improving the image preprocessing effect of the CAPTCHA, which can achieve a better recognition rate by the state-of-the-art machine learning algorithms. There are many kinds of noise and distortion in the CAPTCHA images of this experiment. We propose an adaptive median filtering algorithm based on divide and conquer in this paper. Firstly, the filtering window data quickly sorted… More >

Guorui Huang¹, Zhongkai Cui², Pengfei Zhu¹, Xiaoyun Liu^1,*

CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 145-150, 2018, DOI:10.32604/cmc.2018.02947

Abstract In this paper, a kind of wall fabric’s surface treatment agent modified with nonionic surfactant was reported. This surface treatment agent was prepared by using nano tourmaline powder dispersion in water with surfactant as dispersants by sand milling. Under the influence of different dispersants, the negative ions releasing amount of functional wall fabrics, the milling process and the storage stability of nano tourmaline powder dispersion were discussed. The results showed that nano tourmaline powder dispersion achieved the smallest average diameter of 44 nm and had best storage stability that the average diameter maintained below 200 nm in 17 days when… More >

Yanbin Wang^1,2, Deli Gao¹, Jun Fang¹

CMC-Computers, Materials & Continua, Vol.48, No.1, pp. 57-75, 2015, DOI:10.3970/cmc.2015.048.057

Abstract In this paper, the mechanical model to analyze the riser lateral vibration displacement and stress distribution in installation has been established via variational approach and the principle of minimum potential energy. In this model, the influence of vessel motion on riser lateral vibration has been taken into consideration. The specific expression of lateral vibration has also been figured out according to the boundary conditions and initial conditions. At last, the variations of riser maximum lateral displacement and stress distribution on water depth (WD), wave height, wave period, riser OD, BOPS weight have been discussed. More >

CMC-Computers, Materials & Continua, Vol.47, No.1, pp. 45-63, 2015, DOI:10.3970/cmc.2015.047.045

Abstract A new theory of strain hardening is developed. Important in its own right, the strain hardening solution is also of decisive use in rigorously defining the historically broad concepts of yield stress and failure stress. Under ideal conditions yield stress is found to represent a 3rd order transition. Failure stress is an explicit "failure of function" criterion rather than just being the primitive notion of breaking into pieces. Computational extensions and opportunities are discussed. More >

Qunfeng Liu^1,2, Liang Wang¹, gping Shen¹

CMC-Computers, Materials & Continua, Vol.46, No.2, pp. 105-123, 2015, DOI:10.3970/cmc.2015.046.105

Abstract Molecular dynamics simulations have been performed to investigate the effects of cross section geometry and shape on the mechanical behaviors of silicon nanowires (Si NWs) under tensile loading. The results show that elasticity of <100> rectangular Si NWs depends on their cross section aspect ratios while the elastic limits of <110> and <111> wires show geometry independence. Despite the significant influence of axial orientation, both yield stress and Young's Modulus show the remarkable shape dependence for wires with various regular cross sections. Additionally, underlying mechanism for the geometry and shape effects on mechanical behavior are discussed based on the fundamental… More >

G. Q. Xie^1,2, M. X. Chi¹

CMC-Computers, Materials & Continua, Vol.44, No.2, pp. 123-140, 2014, DOI:10.3970/cmc.2014.044.123

Abstract Dynamic response sensitivity of a simply supported functionally graded magneto-electro-elastic plates have been studied by combining analytical method with finite element method. The functionally graded material parameters are assumed to obey exponential law in the thickness direction. A series solution of double trigonometric function agreed with the simply supported boundary condition is adopted in the plane of the plate and finite element method is used across the thickness of the plate. The finite element model is established based on energy variational principle. The coupled electromagnetic dynamic characteristics of a simply supported functionally graded magneto- electro-elastic plate are decided by its… More >

Haofeng Chen¹

CMC-Computers, Materials & Continua, Vol.20, No.2, pp. 159-184, 2010, DOI:10.3970/cmc.2010.020.159

Abstract In this paper a state-of-the-art numerical method is discussed for the evaluation of the shakedown and ratchet limits for an elastic-perfectly plastic body subjected to cyclic thermal and mechanical load history. The limit load or collapse load, i.e. the load carrying capacity, is also determined as a special case of shakedown analysis. These design limits in plasticity have been solved by characterizing the steady cyclic state using a general cyclic minimum theorem. For a prescribed class of kinematically admissible inelastic strain rate histories, the minimum of the functional for these design limits are found by a programming method, the Linear… More >

W. F. Yuan^1,2, H. B. Zhang¹

CMC-Computers, Materials & Continua, Vol.16, No.2, pp. 117-126, 2010, DOI:10.3970/cmc.2010.016.117

Abstract Corrosion pits on a steel plate can reduce the strength of the plate. However, it is difficult to calculate the corrosion effect analytically since the pits are normally distributed on the plate's surface randomly. In this manuscript, a simple approach is proposed to convert the corroded plate into a perfect one. By this method, the corrosion pits are treated as inclusions embedded in the plate. Then the analytical mechanics model used for composite material can be adopted in the calculation of the steel plate's effective material properties. To verify the proposed approach, numerical simulation is conducted using finite element method. More >