This article investigates the feasibility of utilizing adaptive kinematics to reduce the computational effort of finite element modeling of progressive damage and global failure in fiber-reinforced ...composite laminates. In the present context, adaptive kinematics refers to the selective use of different types of macroscopic laminate models for different regions of the computational domain, based on the solution complexity within each region. Each of these macroscopic laminate models can be distinguished by the manner in which the displacement field is assumed to vary through the thickness of the laminate. In the present study, kinematic adaptivity is made possible through the use of variable kinematic finite elements (VKFE) that are developed by hierarchically combining two or more types of assumed displacement fields in a single finite element domain. The hierarchical data structure of the VKFE greatly simplifies the process of connecting elements that represent different types of laminate theories, thus facilitating adaptive analysis. The adaptive kinematic concept is demonstrated for the bending of simply supported laminates that exhibit diffuse, widespread damage and laminate tensile test specimens that exhibit very intense localized damage due to the free edge effect. The results obtained in this study clearly demonstrate that the use of adaptive kinematics can significantly reduce the overall computational effort of progressive damage solutions without compromising solution accuracy.
In recent years, a series of papers have appeared on algebraic relationships between the solutions (e.g., deflections, buckling loads and frequencies) of a given higher-order plate theory and the ...classical plate theory. The bending relationships, for example, can be used to generate the transverse deflection of a plate according to the particular higher-order theory from the known deflection of the same problem according to the classical plate theory. In the present study relationships between the bending solutions of several higher-order plate theories and the classical plate theory are obtained in a canonical form (i.e., one set of relationships contain several theories and they can be specialized to a specific theory by assigning values to the constants appearing in the relationships). Numerical examples of bending solutions for rectangular plates with various boundary conditions are presented to show how the relations can be used to determine the deflections and bending moments for various theories. The relationships are validated by comparing the numerical results obtained using the relationships for the Mindlin plate theory against those computed using the ABAQUS finite element program.
A series of substituted pyridyl- and quinolinyl-containing 2,4-thiazolidinediones having interesting cyclic amine as a linker have been synthesized. Both unsaturated thiazolidinediones 5 and ...saturated thiazolidinediones 6 and their various salts were evaluated in db/db mice for euglycemic and hypolipidemic effects and compared with BRL compound 11 and BRL-49653, respectively. Some of the potent compounds were converted to various salts in order to obtain improved activities. Among all the salts evaluated, the maleate salt of unsaturated TZD 5a was found to be a very potent euglycemic and hypolipidemic compound. Some of the more interesting compounds have also been evaluated in ob/ob mice and compared with rosiglitazone (maleate salt of BRL-49653). Oral glucose tolerance tests were performed in both db/db and ob/ob mice. Pharmacokinetic studies of 5a maleate are also reported. Receptor binding studies of PPARγ by 5a/5a maleate did not show any significant transactivation of PPARα or PPARγ.
A displacement beam finite element is derived based on a nonlinear kinematic model for a pretwisted composite beam. Elements based on linear, quadratic and cubic interpolation functions are ...developed. The reduced/selective integration technique is employed to investigate shear and membrane locking for each type of element. Various numerical integration rules are examined to determine the best integration scheme. Numerical results are presented on a wide range of beam problems to evaluate the performances of the three types of elements. None of the Gauss quadrature rules investigated, in particular, the three uniform reduced rules, have shown spurious mechanisms. Using the best scheme for each element, the performance studies carried out have shown that the cubic interpolation was the most efficient for almost all the problems studied.
Microsatellites or Simple Sequence Repeats(SSRs) are informative molecular genetic markers in many crop species. SSRs are PCR-based, highly polymorphic, abundant, widely distributed throughout the ...genome and inherited in a co-dominant manner in most cases. Here we describe the presence of SSRs in cDNAs of cotton. Thirty one SSR primer pairs of 220 (∼14%) tested led to PCR amplification of discrete fragments using cotton leaf cDNA as template. Sequence analysis showed 25% of 24randomly selected cDNA clones amplified with different SSR primer pairs contained repeat motifs. We further showed that sequences from the SSR-containing cDNAs were conserved across G. barbadense and G. hirsutum, revealing the importance of the SSR markers for comparative mapping of transcribed genes. Data mining for plant SSR-ESTs from the publicly available databases identified SSRs motifs in many plant species,including cotton, in a range of 1.1 to4.8% of the submitted ESTs for a given species.
In this paper, first-order shear deformation theory (FSDT) is employed to study vibration control of laminated composite plates. The magnetostrictive layers are used to control and enhance the ...vibration suppression via velocity feedback with a constant gain distributed control. Analytical solutions of the equations governing laminated plates with embedded magnetostrictive layers are obtained for simply-supported boundary conditions. The effects of material properties, lamination scheme, and placement of magnetostrictive layers with respect to laminate midplane on vibration suppression are studied in detail.
•Proposed a novel model to find partial periodic-frequent patterns in a database.•Introduced a measure to find partial periodic-frequent patterns in a database.•An efficient pruning technique has ...been proposed to reduce the computational cost.•Described a pattern-growth algorithm to find all partial periodic-frequent patterns•Experimental results show that our model is efficient.
Time and frequency are two important dimensions to determine the interestingness of a pattern in a database. Periodic-frequent patterns are an important class of regularities that exist in a database with respect to these two dimensions. Current studies on periodic-frequent pattern mining have focused on discovering full periodic-frequent patterns, i.e., finding all frequent patterns that have exhibited complete cyclic repetitions in a database. However, partial periodic-frequent patterns are more common due to the imperfect nature of real-world. This paper proposes a flexible and generic model to find partial periodic-frequent patterns. A new interesting measure, periodic-ratio, has been introduced to determine the periodic interestingness of a frequent pattern by taking into account its proportion of cyclic repetitions in a database. The proposed patterns do not satisfy the anti-monotonic property. A novel pruning technique has been introduced to reduce the search space effectively. A pattern-growth algorithm to find all partial periodic-frequent patterns has also been presented in this paper. Experimental results demonstrate that the proposed model can discover useful information, and the algorithm is efficient.
The experiment of two 3×3 complete diallele crosses was carried out with four wild river stocks (Ganga, Yamuna, Brahmaputra and Sutlej) and one farmed stock (Local) of Rohu carp (
Labeo rohita). The ...Local stock was included in both diallele crosses. In total, 864 fish were individually tagged at 6 months of age and reared for 14 months in three monoculture and two polyculture earthen ponds in Orissa, India. For harvest weight, total heterosis for each of the six stock crosses was low or negative and average heterosis was also low and in most cases not significantly different from zero. For survival, total and average heterosis was negligible and not significantly different from zero. It is concluded that genetic improvement through crossbreeding of Indian stocks of Rohu carp has little practical significance.
The mesh-free moving least-squares differential quadrature (MLSDQ) method is proposed for solving the fourth-order, partial differential equation governing the bending of thin plates according to ...classical plate theory. The deflections of an arbitrary shaped plate are expressed in terms of the MLS approximation. The weighting coefficients used in the MLSDQ approximation are calculated through a fast computation of the shape functions and their derivatives. The discrete multiple boundary conditions and governing equations are solved by a least-squares approximation. Numerical examples are presented to illustrate the accuracy, stability and convergence of the present method. Effects of support size, order of completeness and node irregularity on the numerical accuracy are carefully investigated.
This paper presents the development of a semi-analytical axisymmetric shell finite element model with piezoelectric layers using the 3D linear elasticity theory. The piezoelectric effect of the ...material could be used as sensors and/or actuators in way to control shell deformation. In the present 3D axisymmetric model, the equations of motion are expressed by expanding the displacement field using Fourier series in the circumferential direction. Thus, the 3D elasticity equations of motion are reduced to 2D equations involving circumferential harmonics. In the finite element formulation the dependent variables, electric potential and loading are expanded in truncated Fourier series. Special emphasis is given to the coupling between symmetric and anti-symmetric terms for laminated materials with piezoelectric rings. Numerical results obtained with the present model are found to be in good agreement with other finite element solutions.
