Seismic Improvement of Gravity Dams Using Isolation Layer in Contact Area of Dam–Reservoir in Smeared Crack Approach

2018 ◽  
Vol 43 (2) ◽  
pp. 137-155 ◽  
Author(s):  
Amir Pirooznia
Keyword(s):  
Contact Area ◽  
Gravity Dams ◽  
Dam Reservoir ◽  
Isolation Layer ◽  
Smeared Crack Approach ◽  
Smeared Crack

scholarly journals Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hye-gyu Kim ◽  
Wooseok Ji ◽  
Nam Choon Cho ◽  
Jong Kyoo Park
Keyword(s):  
Optimization Algorithm ◽  
Fracture Behavior ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Shear Loading ◽  
Matrix Composites ◽  
Specific Loading ◽  
Smeared Crack Approach ◽  
Smeared Crack

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions.

Experimental and numerical investigation of slabs on ground subjected to concentrated loads

2014 ◽  
Vol 4 (3) ◽  
Author(s):  
Jan Øverli
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Drying Shrinkage ◽  
Element Model ◽  
Experimental Program ◽  
Ultimate Load Capacity ◽  
Smeared Crack Approach ◽  
Linear Behaviour ◽  
Smeared Crack ◽  
Slabs On Ground

AbstractAn experimental program is presented where a slab on ground is subjected to concentrated loading at the centre, the edges and at the corners. Analytical solutions for the ultimate load capacity fit well with the results obtained in the tests. The non-linear behaviour of the slab is captured by performing nonlinear finite element analyses. The soil is modelled as a no-tension bedding and a smeared crack approach is employed for the concrete. Through a parametric study, the finite element model has been used to assess the influence of subgrade stiffness and shrinkage. The results indicate that drying shrinkage can cause severe cracking in slabs on grade.

Numerical Evaluation of Mechanical Parameters Role in GFRP Strengthened Cobblestone Masonry Walls

2017 ◽  
Vol 747 ◽  
pp. 504-511
Author(s):  
Natalino Gattesco ◽  
Alessandra Gubana ◽  
Massimo Melotto
Keyword(s):  
Parametric Study ◽  
Peak Load ◽  
Element Model ◽  
Masonry Wall ◽  
Fiber Reinforced Polymers ◽  
Masonry Walls ◽  
Glass Fiber Reinforced ◽  
Reinforced Masonry ◽  
Smeared Crack Approach ◽  
Smeared Crack

The use of a GFRP (Glass Fiber Reinforced Polymers) mesh, embedded as a reinforcement in a mortar coating on both wall sides, proved to be effective and reliable in increasing the masonry wall resistance and the plastic deformation capacity.In this study, a NL finite element model, developed to predict the in-plane behaviour of masonry walls strengthened by means of this technique, is refined and used in an extensive parametric study. Numerical results were compared with diagonal compression test data on URM and RM cobblestone masonry samples, showing good agreement. The masonry panel and the mortar coating were modelled as isotropic homogeneous materials with a smeared crack approach, whereas the GFRP reinforcement was modelled as a mesh of truss elements. Properties assigned to materials were derived from experimental tests.The parametric study performed before on some involved mechanical properties, considering a standard range of variation, is now extended to other parameters. Moreover, the combined variation of different properties is considered. The actual contribute of each component (masonry, GFRP mesh, mortar) on some macroscopic parameters (strength and ductility of the specimen) is evaluated.The parametric analysis highlights the important role of the GFRP mesh not only on the peak load increment but also on the post-peak behavior and, in particularly, on the ductility increment of the reinforced masonry panel. These results can address the optimization of the intervention technique and the deliverable of operative guidelines for practitioners.

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