varunr14/newsummary huggingface dataset:
Human face can be seen as a soft tissue organ complex with a large investing network of musculature . Due to its complexity most existing computational models approximate these muscular structures using simple geometries such as 1 D curves or primitive 3 D shapes . This paper presents a new approach to evaluate muscle contribution from anatomically accurate geometries while maintaining the computational complexity at a tractable level . In the proposed method 3 D muscle structures are embedded inside a facial continuum where mechanical contribution of muscles is evaluated independently and transferred to the facial computational domain through a finite element mapping procedure . Muscle forces are decomposed into an array of discrete point loads that are determined at the integration points of an appropriate quadrature scheme . As a result muscle meshes can be constructed independent from the facial mesh giving two main advantages the muscle geometries can be refined independent of the facial computational domain and it is not required for the computational domain to conform to complex topology of muscle structures . 


Highlights:
We model the deformation of the human face due to muscle contraction. 3 D muscles with anatomical geometry and fibre orientation is used. Muscle forces are represented as discrete point load at the integration points. Increasing the number of embedded muscles does not increase the degrees of freedom.
In this paper we use a numerical procedure to analyse bifurcation and postbifurcation of inflated hyperelastic thick walled cylinders based on the modified Riks method . In particular the bulging mode of bifurcation is exploited in the context of aneurysm formation with cylindrical geometry in cardiovascular diseases . We focus here on orthotropic materials with two preferred directions which are mechanically equivalent and are symmetrically disposed . Arterial wall tissue is modeled with this class of constitutive equation showing significant stiffening behaviour . The onset of bulging is considered to give aneurysm formation . Analytical solutions can be found in the literature for very particular conditions involving specific material models and loads applied as well as usually a perfect geometry . Here we provide a unified approach to both the prediction of bifurcation and postbifurcation propagation that can be applied to more general conditions . Furthermore we show that bulging instability under the conditions at hand propagates axially in agreement with the propagation of aneurysms in arterial wall tissue . 


Highlights:
Bifurcation and postbifurcation of inflated hyperelastic thick walled cylinders are analysed. Bulging mode of bifurcation is exploited in the context of aneurysm formation. The onset of bulging is considered to give aneurysm formation. Bulging is shown to propagate axially as aneurysms propagate in arterial wall tissue.
In order to investigate the microstructure evolution of inertia friction welding process of FGH96 ring part the dynamic recrystallization kinetic model of FGH96 superalloy was established and a two dimensional axisymmetric coupled thermo mechanical finite element model was developed using the MSC.Marc software . By the second development of MSC.Marc the dynamic recrystallization kinetic model was integrated into the finite element model to simulate the microstructure evolution of inertia friction welding process of FGH96 superalloy . The distributions of dynamic recrystallized fraction and average grain size during the inertia friction welding process were obtained and analyzed . The inertia friction welding experiments of FGH96 ring parts were carried out . The comparison results show that the simulated results agree well with the measured ones . 


Highlights:
A DRX model of FGH96 of IFW process is established. An axisymmetric coupled thermo mechanical FE model of IFW process is established. The microstructure evolution of FGH96 superalloy during IFW process is simulated. The DRX fraction and average grain size during IFW process are predicted accurately.
An efficient approach is proposed in order to predict the mechanical response of complex industrial parts . As these structures are usually composed of massive and thin parts different models have to be mixed together . The transition between these different kinematic assumptions can be problematic and non linear models can not be employed depending on the plate model that is considered . Moreover Finite Element analysis in the case of large and complex assemblies implies tedious meshing steps . The idealization and simplification of these structures into a mix of 2D and 3D Finite Elements usually takes therefore significantly more time than the analysis itself . The objective of the present contribution is to explore a calculation process that enables a simple automation of the meshing steps . Even though potentially computationally more expensive the meshing automation may lead to drastic time reduction for the CAD to mesh process and a much tighter link between CAD and calculated assembly . Finally easier and faster design explorations would be allowed . This strategy relies on the use of a non conforming quadratic approximation that is defined on a sufficiently fine mesh . The eXtended Finite Element Method is used in order to alleviate meshing issues . The mesh and Level Set function are built from the CAD input by means of an automated approach . The strategy is verified against analytical solutions and real aerospace substructures . 


Highlights:
Propose a pragmatic approach for simulating complex industrial parts. Meshing issues avoided thanks to the X FEM. Conversion of the CAD into a Level Set function. Use solid elements in order to treat both slender and massive parts. Encouraging results are shown.
The validity of using the finite element modal analysis in combination with the operational vibration waveforms generated by vehicles to guide structural health monitoring observers in their inspection of old bridges is investigated in this work . A nondestructive vibration based approach operational response and waveform analysis is introduced and used in the process of validating the predictability of the finite element model . In ORWA the frequency domain response of a highway bridge is generated from the operating traffic load and the structural response is visualized and used to develop a holistic view of the bridge s response to automobile loadings . By visualizing the response of the bridge concrete cracking in the abutment and deck is correlated with certain types of structural motion and their corresponding frequencies . Significant excitation frequencies for this particular structure and loading are identified using a frequency domain study of the vibration waveforms generated by vehicle and field results showed similarity with field impact tests conducted on the bridge . The finite element modal analysis of the original CAD drawings of the bridge in combination with the vibration waveforms generated by vehicles spectrum has demonstrated realistic consistency with the findings of ORWA in showing the correlations between the physical damage areas on the bridge and the excited mode shapes of the operational loading that tend to cause these types of damage . 


Highlights:
FE modal analysis based on vehicle waveforms is consistent with the field results. FE modal analysis of original maps can be used to investigate health of old bridges. Major physical damage on the bridge is mainly associated with the first mode. FE modal analysis based on vehicle waveforms can be used to guide bridge inspectors. Bridge s deterioration is associated with the traffic that excites the first mode.
This paper presents a synthesis approach to address the problem of uncertainty in the impact force identification . The effects of material uncertainty on dynamic responses of the structure are studied by using Monte Carlo simulation . Six parameters including mechanical properties and thermal coefficients are considered as independent random variables . A parametric study is conducted to select four parameters as the optimization variables in the following step of model updating . The technique of model updating is used to correct the modeling errors caused by material uncertainty . Then an improved inverse analysis technique based on the finite element method and mode superposition method is taken for impact force identification . In this study the present method is performed on a composite stiffened panel and the effect of noise on the performance of identification is also discussed . The results of the study show that the developed approach is capable of identifying the impact location and reconstructing the force history accurately by reducing material uncertainty through the modal updating procedure . 


Highlights:
A hybrid method to address uncertainty effects in the impact force identification is presented. A parametric study is conducted to analyze the effects of material uncertainty on dynamic responses of composite stiffened panels. The technique of model updating is used to correct the modeling errors caused by material uncertainty. An improved inverse analysis technique based on FEM and mode superposition method is taken for impact force identification. The proposed method is validated on the composite stiffened panel and the effect of noise is finally discussed.
The objective of the paper is to investigate the applicability of a model order reduction technique for dynamic simulation of beams with forcing and geometric nonlinearities . A cantilever and a doubly clamped beams actuated by an electrostatic force are considered in the paper . The governing partial differential equations for the two cases which account for the nonlinearities are presented . These equations are spatially discretized using the Galerkin finite element method . The resulting system of nonlinear ordinary differential equations is reduced using the trajectory piecewise linear model order reduction method . Simulation indicates that the use of the original TPWLMOR method leads to the presence of a phase error in the long term dynamic simulation of the models . To improve the accuracy of the dynamic response a modification to the original TPWLMOR based on minimization of residual at linearization point is proposed . Further the parameters affecting the accuracy of the modified TPWLMOR are studied . 


Highlights:
We study the applicability of Trajectory Piecewise Linear Model Order Reduction TPWLMOR method for dynamic simulation of nonlinear beam problems. Nonlinearities which include both forcing and geometric nonlinearities are considered. To improve accuracy of TPWMLOR a new method is suggested based on minimization of residual at linearization point. Factors affecting the accuracy of the modified TPWLMOR are studied in detail.
In modern finite element analysis a mesh is said to be tangled if it contains one or more inverted elements . Tangling can occur for example during mesh optimization and mesh morphing . Modern finite element theory and commercial FEA packages are not designed to handle tangled meshes i.e . they can lead to erroneous results . Researchers and practitioners therefore unanimously recommend untangling prior to analysis . In this paper a new mathematical framework for FEA over tangled meshes is proposed . Specifically by defining a cell decomposition of a tangled mesh and an associated set of cell shape functions it is shown that FEA can be successfully carried out over tangled meshes . The cell shape functions are constructed through an oriented linear combination of the classic element shape functions . Numerical examples illustrate the correctness of the proposed framework . Potential applications of the proposed framework are also illustrated . 


Highlights:
A new theory is proposed for finite element analysis over a tangled mesh. The theory rests on cell decomposition and cell shape functions. The theory extends continuous Galerkin formulation to a tangled mesh. Numerical results are provided to validate the proposed theory.
Many problems in structural mechanics involve complex principal stress fields that are not orthogonal to the geometric axis of the structure . Such problems are often analysed with finite elements but the quality of a finite element solution may be sensitive to the orientation of the mesh with respect to the principal axes of stress . This paper presents the outline of a procedure to generate well structured inclined quadrilateral finite element meshes for the analysis of thin plate and shell structures . The procedure was developed using the commercial FE pre processor ABAQUS CAE and the Python script language though it may readily be applied in any pre processor which supports an external scripting functionality . A set of mesh convergence studies using linear buckling analyses are presented on four benchmark problems with known analytical solutions to illustrate the effect of inclined meshes on the accuracy of the computed solution . These illustrations are intended to raise an awareness of the subtle but important relationship between mesh and stress field orientation and are presented for the benefit of practising finite element analysts in structural engineering . 


Highlights:
Analysis of plate and shell structures may involve inclined principal stress fields. Such fields may cause buckling modes that are not orthogonal to the geometric axes. In such cases the finite element solution is sensitive to the mesh orientation. Studies show that rectangular elements subject to pure shear converge more slowly. Highly relevant to shell analysts modelling structures in global shear and torsion.
Interviews were conducted with thirteen professional designers to understand their attitudes towards fixation and the practices they adopt to address it . Fixation was thought to be encouraged and discouraged by a wide range of factors related to the project the client the design team the organisational culture and the design activities employed . The experiences that designers accumulate during their professional lives were associated with fixation in different ways . The experience of prior design failures was thought to encourage fixation whilst the experience of varied solutions was thought to discourage fixation . Recognising fixation episodes and reflecting on them was described as the means by which designers could guard against such episodes in the future and thus be more creative . 


Highlights:
Interview study with expert designers. Design fixation is a real problem in professional practice. Designers are aware of fixation and take steps to address it. Fixation is influenced by a wide range of contextual factors. Reflecting on fixation helps designers to guard against it.
The aim of this work is the numerical study of a crack path in a residual stress field resulting from a manufacturing process such as quenching . An XFEM technique is proposed to that end and the example illustrating the quenching of a large thick plate is considered so as to demonstrate the capability of the method proposed . Indeed during the quenching of steels metallurgical transformations can occur leading to high residual stresses at room temperature . From the practical point of view the thick plate must be sawn after quenching . But it is experimentally observed that under certain quenching conditions the crack initiated by the sawing suddenly propagates through the thickness of the plate and then rotates through an angle of about 90 . The numerical simulation of quenching is detailed and the results obtained under two operating conditions are given . Then the XFEM technique applied to the crack propagation in a residual stress field is presented and the cracking path obtained on the quenched plate is compared to that obtained using the FEM coupled with a remeshing technique . It is shown that the computed crack path justifies experimental observations . 


Highlights:
Simulation of mechanical effects due to water quenching of a large thick plate made of 40CMD8 steel. Study of the influence of operating parameters on residual stresses with FEM. Application of XFEM to simulate a crack s path observed experimentally which is initiated by the sawing of the plate. The results demonstrate the relevance of XFEM to study cracking problems through residual stress fields computed with FEM.
A continuum finite element model for the nanoscale plates considering the surface effect of the material is developed . Governing equations for Kirchoff and Mindlin nanoplates are derived by using the Galerkin finite element technique . The model is verified by comparing the results with available analytical solutions . The results indicate that depending on the boundary conditions the deflections and frequencies of the plate have a dramatic dependence on the residual surface stress and surface elasticity of the plates . The present model is an efficient tool for the analysis of the static and dynamic mechanical behaviors of nanoscale plates with complex geometry boundary and loading conditions and material properties . 


Highlights:
A continuum finite element model for the bending and vibration behaviors of nanoscale plates is developed. Effects of residual surface stress and surface elasticity are included in the model. The model is an efficient tool for the analysis and design of nanoscale plate devices.
A hybrid finite element formulation is developed by using the Hellinger Reissner functional which is obtained from the complementary energy functional for pre buckling and buckling analysis of thin walled beams by introducing element equilibrium and force boundary conditions as auxilary conditions . Comparison to the complementary energy based formulation the current hybrid formulation is advantageous because it does not require the satisfaction of inter element force equilibrium a priori and therefore it is easily adaptable within the existing displacement based thin walled beam finite element analysis codes for which the assemblage procedure is relatively easy . Comparison to the displacement based formulations the current hybrid formulation has the advantage of incorporating the shear deformation effects easily by using the strain energy of the shear stress field without modifying the basic kinematic assumptions of the thin walled beam theory . In the current formulation the effects of load position can also be easily captured by virtue of the freedom provided in the beam axis selection . Comparisons with solutions from literature and those based on shell element models are presented and an example is designated to illustrate the significance of shear deformation effect . 


Highlights:
Hellinger Reissner functionals for pre buckling and buckling analysis are obtained from the complementary energy functional. Current formulation is advantageous because it does not require a priori satisfaction of the inter element force equilibrium. Comparison to the displacement based formulations the current formulation has the advantage of incorporating the shear deformation effects without modifying the kinematic assumptions. The effects of load position can also be easily captured by virtue of the freedom provided in the beam axis selection.
More and more large data collections are gathered worldwide in various IT systems . Many of them possess a networked nature and need to be processed and analysed as graph structures . Due to their size they very often require the usage of a parallel paradigm for efficient computation . Three parallel techniques have been compared in the paper MapReduce its map side join extension and Bulk Synchronous Parallel . They are implemented for two different graph problems calculation of single source shortest paths and collective classification of graph nodes by means of relational influence propagation . The methods and algorithms are applied to several network datasets differing in size and structural profile originating from three domains telecommunication multimedia and microblog . The results revealed that iterative graph processing with the BSP implementation always and significantly even up to 10 times outperforms MapReduce especially for algorithms with many iterations and sparse communication . The extension of MapReduce based on map side join is usually characterized by better efficiency compared to its origin although not as much as BSP . Nevertheless MapReduce still remains a good alternative for enormous networks whose data structures do not fit in local memories . 


Highlights:
We compared three parallel computing techniques in terms of large graph processing. MapReduce map side join and Bulk Synchronous Parallel tested for two distinct problems. Iterative graph processing with the BSP implementation significantly outperforms MapReduce. Map side join design pattern may improve the original MapReduce performance.
The execution context in which pervasive systems or mobile computing run changes continually . Hence applications for these systems require support for self adaptation to the continual context changes . Most of the approaches for self adaptive systems implement a reconfiguration service that receives as input the list of all possible configurations and the plans to switch between them . In this paper we present an alternative approach for the automatic generation of application configurations and the reconfiguration plans at runtime . With our approach the generated configurations are optimal as regards different criteria such as functionality or resource consumption . This is achieved by modelling architectural variability at design time using the Common Variability Language and using a genetic algorithm that finds nearly optimal configurations at run time using the information provided by the variability model . We also specify a case study and we use it to evaluate our approach showing that it is efficient and suitable for devices with scarce resources . 


Highlights:
We specify an approach for the dynamic reconfiguration of mobile applications. We model a mobile application with variability which can be reconfigured at runtime. We simulate the execution of the mobile application when our dynamic reconfiguration service is applied and not applied respectively. We measure the battery life as well as the overall utility of the application perceived by the user. Applying our dynamic reconfiguration the battery life is incremented by 45.9 and the utility is incremented by 10.31 .