D. Pandit¹, N. Thomas², Bhakti Patel¹, S.M. Srinivasan¹

CMC-Computers, Materials & Continua, Vol.45, No.2, pp. 127-144, 2015, DOI:10.3970/cmc.2015.045.127

Abstract In this paper, a class of problems involving space constrained loading on thin beams with large deflections is considered. The loading is such that, the locus of the force application point moves along an arbitrarily predefined path, fixed in space. Both linear elastic as well as elastic-perfectly plastic materials are considered. A simplification is realized using the moment-curvature relationship directly. The governing equation obtained is highly non-linear owing to inclusion of both material and geometric non-linearity. A general algorithm is described to solve the governing equation using an incremental formulation coupled with Runge Kutta 4^th order initial value explicit solver.… More >

Vishal Shreyans Shah¹, Henyl Rakesh Shah², Pijush Samui³, A. Ramachra Murthy⁴

CMC-Computers, Materials & Continua, Vol.44, No.2, pp. 73-84, 2014, DOI:10.3970/cmc.2014.044.073

Abstract This paper deals with the development of models for prediction of facture parameters, namely, fracture energy and ultimate load of high strength and ultra high strength concrete based on Minimax Probability Machine Regression (MPMR) and Extreme Learning Machine (ELM). MPMR is developed based on Minimax Probability Machine Classification (MPMC). ELM is the modified version of Single Hidden Layer Feed Foreword Network (SLFN). MPMR and ELM has been used as regression techniques. Mathematical models have been developed in the form of relation between several input variables such as beam dimensions, water cement ratio, compressive strength, split tensile strength, notch depth, and… More >

Ananthalakshmi K. Iyer¹, A. Rama Chra Murthy², Smitha Gopinath², Nagesh R. Iyer³

CMC-Computers, Materials & Continua, Vol.42, No.3, pp. 227-244, 2014, DOI:10.3970/cmc.2014.042.227

Abstract A non-linear fracture mechanics based approach is proposed to depict a typical fracture mechanism from initiation to growth, eventually leading to failure. This concept is developed for a lightly reinforced beam in flexure. The proposed model integrates the existing methodology of a Stress Intensity Factor equilibrium equation with the bridging forces developed in concrete cover and rebar. The model and solution algorithm outlined presents an elaborate understanding of the mechanism involved and is significant in predicting the behaviour of flexural members. The analysis is performed using MATLAB programming. The proposed approach ensures a maximum tolerable crack length and crack width… More >

Yuvaraj P¹, A Ramachra Murthy², Nagesh R Iyer³, S.K. Sekar⁴, Pijush Samui⁵

CMC-Computers, Materials & Continua, Vol.41, No.3, pp. 193-214, 2014, DOI:10.3970/cmc.2014.041.193

Abstract This paper presents fracture mechanics based Artificial Neural Network (ANN) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (Gf), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). Failure load of the beam (Pmax) is also predicated by using ANN model. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack tip opening displacement have been outlined. Back-propagation training technique has been employed for updating… More >

Jung Soo Lee¹, Sung Yong Park², Keunhee Cho², Jeong-Rae Cho², Seung Hee Kwon^1,3

CMC-Computers, Materials & Continua, Vol.41, No.2, pp. 85-110, 2014, DOI:10.3970/cmc.2014.041.085

Abstract The objective of this study is to investigate the differences between the tensile stress-crack opening relationships of the small size notched beam and the real size beam which were made of two ultra-high performance fiber reinforced concretes (UHPFRCs) having different volume fractions and lengths of fibers. The stress-crack opening relationships of two UHPFRCs were first obtained from the inverse analysis for the small size notched beam tests. In addition, the three types of real size beams were manufactured for each mix: (1) plain beam, (2) beam with tensile reinforcement, and (3) beam with both tensile and compressive reinforcements. The flexural… More >

Leiting Dong¹, Ahmed S. El-Gizawy², Khalid A. Juhany², Satya N. Atluri³

CMC-Computers, Materials & Continua, Vol.40, No.1, pp. 49-78, 2014, DOI:10.3970/cmc.2014.040.049

Abstract In this study, a simple 4-node locking-alleviated mixed finite element (denoted as CEQ4) is developed, for the modeling of homogeneous or functionally graded or laminated thick-section composite beam structures, without using higher-order (in the thickness direction) or layer-wise zig-zag theories of composite laminates which are widely popularized in current literature. Following the work of [Dong and Atluri (2011)], the present element independently assumes a 5-parameter linearly-varying Cartesian strain field. The independently assumed Cartesian strains are related to the Cartesian strains derived from mesh-based Cartesian displacement interpolations, by exactly enforcing 5 pre-defined constraints at 5 pre-selected collocation points. The constraints are… More >

Yongze Cao¹, Guojian Li¹, Qiang Wang^1,2, Xiaoguang Wang³, Jiaojiao Du¹, Jicheng He¹

CMC-Computers, Materials & Continua, Vol.37, No.3, pp. 195-203, 2013, DOI:10.3970/cmc.2013.037.195

Abstract The Fe₆₀Ni₄₀ (in atomic %) polycrystalline thin films with 90 nm thickness were prepared on 200 °C quartz substrate by using molecular beam vapor deposition method. The influence of 0 T and 6 T magnetic fields on the structural evolution and magnetic properties of thin films was studied by using EDXS, XRD, AFM and VSM. In this study, only α phase was formed in both thin films. It was found that the application of a 6 T magnetic field obviously decreases the RMS of surface roughness and the grain size. For the magnetic properties of the thin films, the 6… More >

P. Yuvaraj¹, A. Ramachandra Murthy², Nagesh R. Iyer³, Pijush Samui⁴, S.K. Sekar⁵

CMC-Computers, Materials & Continua, Vol.36, No.1, pp. 73-97, 2013, DOI:10.3970/cmc.2013.036.073

Abstract This paper presents Multivariate Adaptive Regression Splines (MARS) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (GF), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). This paper also presents the details of development of MARS model to predict failure load (Pmax) of high strength concrete (HSC) and ultra high strength concrete (UHSC) beam specimens. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack… More >

A Rama Chandra Murthy¹, Smitha Gopinath^1,2, Ashish Shrivastav¹, G. S. Palani¹, Nagesh R. Iyer¹

CMC-Computers, Materials & Continua, Vol.25, No.1, pp. 1-18, 2011, DOI:10.3970/cmc.2011.025.001

Abstract This paper presents methodologies for crack growth study and fatigue remaining life prediction of reinforced concrete structural components accounting for the corrosion effects. Stress intensity factor (SIF) has been computed by using the principle of superposition. At each incremental crack length, net SIF has been computed as the difference of SIF of plain concrete and reinforcement. The behaviour of reinforcement has been considered as elasto-plastic. Uniform corrosion rate has been assumed in the modeling. Corrosion effect has been accounted in the form of reduction in the diameter and modulus of elasticity of steel. Numerical studies have been carried out to… More >

M.F. Liu¹

CMC-Computers, Materials & Continua, Vol.22, No.2, pp. 97-128, 2011, DOI:10.3970/cmc.2011.022.097

Abstract A new invented Orthogonal Tapered Beam Functions (OTBFs) have been introduced in this paper and used in accordance with the Rayleigh-Ritz method to determine the natural frequencies and mode shapes of the non-uniform rectangular isotropic plates with varying thickness in one or two directions. The generation of the OTBFs is based on the static solution of a one-dimensional beam problem subjected to constant applied load, and then extends to an orthogonal or orthonomal infinite set of admissible functions by performing the three-term recurrence scheme. A wide range of non-uniform rectangular plate whose domain is referenced by a so-called truncation factor… More >