Bingji Lan¹, Kanghao Yan^{1, *}

CMC-Computers, Materials & Continua, Vol.62, No.3, pp. 1303-1315, 2020, DOI:10.32604/cmc.2020.06584

Abstract In order to study the wind-induced vibration control effect of the viscous damper on the large-scale substation frame, this paper takes the large-scale 1000 kV substation frame of western Inner Mongolia as an example. The time-history sample of pulsating wind load is simulated by harmonic superposition method based on Matlab software. 6 kinds of viscous damper arrangement schemes have been designed, and SAP2000 finite element software is used for fine modeling and input wind speed time history load for nonlinear time history analysis. The displacement and acceleration of a typical node are the indicators of… More >

Haitao Luo¹, Jia Fu¹, Rong Chen¹, Peng Wang²

Intelligent Automation & Soft Computing, Vol.25, No.4, pp. 855-864, 2019, DOI:10.31209/2019.100000089

Abstract Space payloads which installed on spacecraft such as satellites and airships are usually experienced random vibrations and low-frequency sinusoidal vibrations during launching. In this paper, a space payload cabinet is introduced, and the damping design is carried out by applying constrained viscoelastic damping layer to the surfaces of the cabinet to ensure that the space payloads can withstand the above-mentioned mechanical environmental conditions. A reliable connection between the space payload cabinet and the shaking table is achieved through the vibration test fixture. The basic requirements for the function and design of the vibration test fixture More >

A. C. Michel-Aceves¹, J. F. Díaz-Nájera¹, R. Ariza-Flores², M. A. Otero-Sánchez¹, R. Escobar-Martínez¹ and C. H. Avendaño-Arrazate^3,*

Phyton-International Journal of Experimental Botany, Vol.88, No.3, pp. 325-333, 2019, DOI:10.32604/phyton.2019.06777

Abstract In two tomato genotypes, we assessed control alternatives for damping-off with combinations of chemical fungicides and native/commercial strains of biological agents. Forty treatments consisting of 19 levels of mixing products, chemical fungicides, native strains and commercial products from biological control agents, and untreated treatment were used onto Ramsés and Toro hybrids. They were distributed on an incomplete block design in divided plots arrangement, where genotypes constitute the larger ones and the 8-repetition mixed products, the smaller ones. Putting 180 mL of fungal complexes, made of spores and mycellium Fusarium-solani (2 × 106 UFC), Rhizoctonia-solani (1… More >

Khouloud Cheour^1,*, Mustapha Assarar¹, Daniel Scida¹, Rezak Ayad¹, Xiaolu Gong²

Journal of Renewable Materials, Vol.7, No.9, pp. 877-889, 2019, DOI:10.32604/jrm.2019.06826

Abstract The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites. Therefore, various staking sequences of glass-flax hybrid composites were manufactured and tested in free vibrations. The damping coefficients were identified by fitting the experimental responses of free-free bending vibrations. The obtained results show that the staking sequences and the position of flax fiber layers in the hybrid composites changed the properties, so a classification of different stacking sequences was established. In fact, the hybrid laminate made of two glass external layers placed on both sides More >

Fatima Ezzahra El Abbassi^1,*, Mustapha Assarar², Rezak Ayad², Hamid Sabhi², Stephane Buet², Nouzha Lamdouar³

Journal of Renewable Materials, Vol.7, No.3, pp. 253-267, 2019, DOI:10.32604/jrm.2019.01759 - 14 July 2021

Abstract This paper aims at studying the effect of recycling on the static and dynamic properties of short alfa fibre reinforced polypropylene. For this purpose, alfa fibres reinforced composites were elaborated by an injection moulding process and were subjected to different mechanical recycling cycles. Then, non-recycled and recycled materials were subjected to static tests and Dynamic Mechanical Analysis (DMA) to evaluate the effect of recycling on their behaviour. Besides, the effects of alkali and salt water treatments on the static and dynamic properties of the alfa composite were also investigated. The obtained results show that tensile More >

Liang Wu¹, Xiaorui Xiang¹, Yang Chen¹, Karrech Ali^2,*, Junru Zhou^1,*, Ming Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.2, pp. 421-443, 2019, DOI:10.32604/cmes.2019.05218

Abstract During the excavation of deep rock, a sudden change in boundary conditions will cause the in-situ stress on the excavation surface to release instantaneously. This disturbance propagates in the form of an unloading stress wave, which will enlarge the damage field of surrounding rock. In this paper, the dynamic unloading problem of the in-situ stress in deep rock excavation is studied using theoretical, numerical, and experimental methods. First, the dynamic unloading process of rock is analyzed through adopting the wave equation, and the equivalent viscous damping coefficient of the material is taken into consideration. Calculations More >

Claude Prost, Bruno Abdelnour

Sound & Vibration, Vol.52, No.2, pp. 7-10, 2018, DOI:10.32604/sv.2018.03641

Abstract Wire Rope Isolators (WRI) are well known and used for the protection of sensitive equipment against non-contact underwater explosions (UNDEX) on board Naval Ships, amongst others, which are extremely destructive and can comple`tely impair the ship’s combat capability.
Traditional WRI exhibit a number of definite advantages, such as large deflection capability, modularity and insensitivity to aggressive environment when proper materials are used. However, their inherent nonlinearity does not always provide the best solution in terms of shock attenuation. (Stiffening tension characteristics)
Fortunately, there are ways to overcome this problem, namely increasing their damping and/ or changing… More >

Mohammad Hossein Ghadiri Rad¹, Farzad Shahabian^1,2, Seyed Mahmoud Hosseini³

CMES-Computer Modeling in Engineering & Sciences, Vol.108, No.3, pp. 135-157, 2015, DOI:10.3970/cmes.2015.108.135

Abstract A meshless method based on the local Petrov-Galerkin approach is developed for elasto-dynamic analysis of geometrically nonlinear two dimensional (2D) problems in hyper-elastic functionally graded materials. The radial point interpolation method (RPIM) is utilized to build the shape functions and the Heaviside step function is used as the test function. The mechanical properties of functionally graded material are considered to continuously vary in a certain direction and are simulated using a nonlinear power function in volume fraction form. Considering the large deformations, it is assumed that the domain be made of large deformable neo-Hookean hyperelastic… More >

Priyankar Datta¹, Manas C. Ray¹

CMC-Computers, Materials & Continua, Vol.49-50, No.1, pp. 47-80, 2015, DOI:10.3970/cmc.2015.049.047

Abstract This paper deals with the implementation of the one dimensional form of the fractional order derivative constitutive relation for three dimensional analysis of active constrained layer damping (ACLD) of geometrically nonlinear laminated composite plates. The constraining layer of the ACLD treatment is composed of the vertically/obliquely reinforced 1–3 piezoelectric composites (PZCs). The von Kármán type nonlinear strain displacement relations are used to account for the geometric nonlinearity of the plates. A nonlinear smart finite element model (FEM) has been developed. Thin laminated substrate composite plates with various boundary conditions and stacking sequences are analyzed to More >

J.R. Lin¹, L.M. Chu², T.L. Chou³, L.J. Liang³, P.Y. Wang³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.2, pp. 163-177, 2014, DOI:10.3970/fdmp.2014.010.163

Abstract We investigate the influence of non-Newtonian micropolar fluids on the dynamic characteristics of wide tapered-land slider bearings. The study is carried out on the basis of the micro-continuum theory originally developed by Eringen (1966). Analytical expressions for the linear dynamic coefficients are provided and compared with earlier results in the literature. In particular, direct comparison with the Newtonian fluid-lubricated tapered-land bearings by Lin et al. (2006) indicates that the use of non-Newtonian micropolar fluids can lead to a significant increase in the values of stiffness and damping coefficients. Such improvements are found to be even More >