scholarly journals Efficient modelling of delamination growth using adaptive isogeometric continuum shell elements

2019 ◽  
Vol 65 (1) ◽  
pp. 99-117 ◽  
Author(s):  
Camiel Adams ◽  
Martin Fagerström ◽  
Joris J. C. Remmers
Keyword(s):  
Isogeometric Analysis ◽  
Shell Element ◽  
Lead Times ◽  
Computationally Efficient ◽  
Shell Elements ◽  
Delamination Growth ◽  
Modelling Framework ◽  
Solution Methods ◽  
Efficient Prediction ◽  
Efficient Approximation

Abstract The computational efficiency of CAE tools for analysing failure progression in large layered composites is key. In particular, efficient approximation and solution methods for delamination modelling are crucial to meet today’s requirements on virtual development lead times. For that purpose, we present here an adaptive continuum shell element based on the isogeometric analysis framework, suitable for the modelling of arbitrary delamination growth. To achieve an efficient procedure, we utilise that, in isogeometric analysis, the continuity of the approximation field easily can be adapted via so-called knot insertion. As a result, the current continuum shell provides a basis for an accurate but also computationally efficient prediction of delamination growth in laminated composites. Results show that the adaptive modelling framework works well and that, in comparison to a fully resolved model, the adaptive approach gives significant time savings even for simple analyses where major parts of the domain exhibit delamination growth.

Computational Investigation of through the Width Delamination of a Composite Laminate using Surface based Cohesive Contact Behaviour

2021 ◽  
Vol 9 (VI) ◽  
pp. 743-747
Author(s):  
K. S. Vishwanath
Keyword(s):  
Composite Laminate ◽  
Weight Ratio ◽  
Computational Prediction ◽  
Shell Elements ◽  
Delamination Growth ◽  
Reinforced Polymer ◽  
Contact Behaviour ◽  
Out Of Plane ◽  
Growth Initiation ◽  
Polymer Laminates

The fiber reinforced polymer laminates have found extensive applications because of its advantages over other materials in terms of strength to weight ratio, manufacturing flexibility and so on. But in the transverse direction, strength is comparatively less so that a failure mechanism called delamination will occur in case of poor manufacturing or when tools are dropped. In this paper, Surface based Cohesive contact behavior is implemented at the interface between base and sub laminate to investigate for 60mm through the width buckling driven delamination growth. The computational prediction of delamination growth initiation is obtained by solving a HTA/6376C composite laminate specimen for geometric non linearity using SC8R continuum shell elements of Abaqus CAE and by plotting the inplane loads versus out of plane displacements.

A Finite Element for the Analysis of Shell Intersections

1996 ◽  
Vol 118 (4) ◽  
pp. 399-406 ◽  
Author(s):  
W. J. Koves ◽  
S. Nair
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Three Dimensional ◽  
Shell Element ◽  
Theory Of Elasticity ◽  
Shell Elements ◽  
Asme Code ◽  
Form Theory ◽  
Computation Scheme ◽  
Shell Intersections

A specialized shell-intersection finite element, which is compatible with adjoining shell elements, has been developed and has the capability of physically representing the complex three-dimensional geometry and stress state at shell intersections (Koves, 1993). The element geometry is a contoured shape that matches a wide variety of practical nozzle configurations used in ASME Code pressure vessel construction, and allows computational rigor. A closed-form theory of elasticity solution was used to compute the stress state and strain energy in the element. The concept of an energy-equivalent nodal displacement and force vector set was then developed to allow complete compatibility with adjoining shell elements and retain the analytical rigor within the element. This methodology provides a powerful and robust computation scheme that maintains the computational efficiency of shell element solutions. The shell-intersection element was then applied to the cylinder-sphere and cylinder-cylinder intersection problems.

scholarly journals Modelling of confined masonry structure and its application for the design of multi-story building

2019 ◽  
Vol 276 ◽  
pp. 01034
Author(s):  
Made Sukrawa ◽  
Gede Pringgana ◽  
Putu Ayu Ratih Yustinaputri
Keyword(s):  
Maximum Stress ◽  
Residential Building ◽  
Shell Element ◽  
Reinforced Concrete Beams ◽  
Seismic Load ◽  
Confined Masonry ◽  
Shell Elements ◽  
Wall Strength ◽  
Story Building ◽  
Better Than

The confined masonry (CM) structure has been commonly used in the construction of one-story buildings in Indonesia. Its application for multi-story buildings however, is not yet as popular as the alternative options. This research numerically investigated the behavior of confined masonry and its application for use as the main structure of multi-story buildings subjected to seismic loading. From the validation models it was revealed that, using shell element for masonry walls, reinforced concrete beams and tie-columns, the CM model mimic the load deformation curve of tested specimen better than that using frame and shell elements. The application of the modeling technique for the design of 3-story residential building using wall density index less than that suggested in the literature resulted in a safe and stiff structure. The wall stresses under design seismic load were still less than the wall strength and the drift ratio of the model was 0.06% much smaller than the limit of 0.2%. The maximum stress observed at the corners of wall opening justify the need for confinement along the opening.

Deformation Modeling of Compliant Robotic Fingers Grasping Soft Objects

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Nicolas Mouazé ◽  
Lionel Birglen
Keyword(s):  
Experimental Testing ◽  
Simple Algorithm ◽  
Accurate Estimation ◽  
Computationally Efficient ◽  
Dynamic Simulations ◽  
Potential Applications ◽  
Classical Models ◽  
Soft Objects ◽  
Efficient Approximation ◽  
Robotic Fingers

Abstract In this paper, a model is shown to predict the simultaneous deformations occurring when compliant robotic fingers are grasping soft objects. This model aims at providing an accurate estimation of the penetration, internal forces, and deformed shapes of both these fingers and the objects. A particular emphasis is placed on the case when the finger is underactuated but the methodology discussed in this paper is general. Usually in the literature, underactuated fingers are modeled and designed considering their grasps of rigid object because of the complexity associated with deforming objects. This limitation severely hinders the usability of underactuated grippers and either restricts them to a narrow range of applications or requires extensive experimental testing. Furthermore, classical models of underactuated fingers in contact with objects are typically applicable with a maximum of one contact per phalanx only. The model proposed in this paper demonstrates a simple algorithm to compute a virtual subdivision of the phalanges which can be used to estimate the contact pressure arising when there are contacts at many locations simultaneously. This model also proposes a computationally efficient approximation of isotropic soft objects. Numerical simulations of the proposed model are compared here with dynamic simulations, finite element analyses, and experimental measurements which all shows its effectiveness and accuracy. Finally, the extension of the model to other types of underactuated fingers, standard grippers, and fully actuated robotic fingers as well as potential applications is discussed and illustrated.

scholarly journals RESPON SEISMIK STRUKTUR RANGKA DINDING PENGISI YANG DIMODEL DENGAN ELEMEN SHELL PENUH DAN PARSIAL

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Putu Ratna Suryantini ◽  
M. Sukrawa ◽  
I. A. M Budiwati
Keyword(s):  
Shell Model ◽  
3D Structure ◽  
Shell Element ◽  
Maximum Load ◽  
3D Models ◽  
Frame Structure ◽  
Natural Period ◽  
Shell Elements ◽  
Frame Model ◽  
Wall Strength

Abstract: Research on the seismic response of in-filled frame structure has been done with in-filled frame model as full and partial shell elements. The wall is considered active until the maximum load on the full shell models, while the partial shell model using the gradual load with the strength of the wall is considered inactive if the stress of the wall exceeded the wall strength The 4 storey hotel building with full wall in x-direction and wall with opening in y-direction were modeled in SAP 2000 as 3D infilled-frame using full and partial shell element. In Mxy models, both wall were included in the model, while in My models, only the wall in y-direction included. Therefore, 4 models were obtained, there are full shell model MxyShPn and MyShPn and partial shell model MyShPar and MyShPar. In addition, 2 diagonal strut models MxyS and MyS  and an open frame model MOF were made as comparison. Prior to model 3D structure, validation models were created using test result condited by other as reference. For that purphose 5 2D models were created there are open frame model MOF, single strut model MST, multiple strut model MSG, full shell model MShPn and  partial shell model MShPar. From validation models, it is apparent that the MxyShPar model mimic the behavior of tested structure better than the other models. From the 3D models analysis result show that the displacement in x-direction of MxyShPn, MxyShPar, MxyS were 89%, 85%, 84% smaller than those of MOF, respectively inclusion of wall in the models, also reduce the internal forces and reduse the natural period of the sctructure.

Simulating welding with shell elements

2004 ◽  
Vol 120 ◽  
pp. 347-354
Author(s):  
F. Faure ◽  
J.-M. Bergheau ◽  
J.-B. Leblond
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Shell Element ◽  
Thermal Calculation ◽  
Transformation Plasticity ◽  
Thin Structures ◽  
Shell Elements ◽  
Mechanical Calculation ◽  
Complex Interactions ◽  
Mechanical Phenomena

Finite element simulations can be used to evaluate residual stresses and distortions induced by welding. Such simulations must account for complex interactions between thermal, metallurgical and mechanical phenomena. “Local” simulations are often sufficient for satisfactory predictions of residual stresses in the heat-affected zone (HAZ), but 3D “global” simulations are often necessary to calculate distortions, which can be important even far from the HAZ. In order to avoid such heavy calculations, a special shell element is proposed for the simulation of welding of thin structures. The thermal calculation involves only one nodal degree of freedom but fully accounts for boundary conditions on the faces of the shell. The metallurgical and mechanical calculations are based on a “multi-layer” approach. Due account is taken of transformation plasticity in the mechanical calculation. Numerical results obtained with this approach are compared to those of experiments and some 3D simulation.

scholarly journals Predicting the emission wavelength of organic molecules using a combinatorial QSAR and machine learning approach

RSC Advances ◽  
2020 ◽  
Vol 10 (40) ◽  
pp. 23834-23841
Author(s):  
Zong-Rong Ye ◽  
I.-Shou Huang ◽  
Yu-Te Chan ◽  
Zhong-Ji Li ◽  
Chen-Cheng Liao ◽  
...  
Keyword(s):  
Machine Learning ◽  
Organic Molecules ◽  
Fluorescence Emission ◽  
Emission Wavelength ◽  
Learning Approach ◽  
Computationally Efficient ◽  
Machine Learning Approach ◽  
Efficient Prediction

The combinatorial QSAR and machine learning approach provides the qualitative and computationally efficient prediction for fluorescence emission wavelength of organic molecules.

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