Abstract null null We present a stochastic modeling framework to represent and simulate spatially-dependent geometrical uncertainties on complex geometries. While the consideration of random geometrical perturbations has long been a subject of interest in computational engineering, most studies proposed so far have addressed the case of regular geometries such as cylinders and plates. Here, standard random field representations, such as Karhunen–Loeve expansions, can readily be used owing, in pa...
Abstract null null The variational formulation of coupled mechanical problems has many advantages from the theoretical point of view and also guides the design of numerical methods that have attractive features such as symmetric tangents. In the current work we propose a novel variational principle for three-field, strongly coupled problems involving (inelastic, finite strain) mechanics, thermal transport, and mass diffusion. To obtain this result, it is key to redefine dissipative phenomena as ...
Abstract null null null null To model null fiber failures null null in random fiber networks, we have developed an elastoplastic Timoshenko beam finite element with embedded discontinuities. The method is based on the theory of strong discontinuities where the generalized displacement field is enhanced by a jump. The null continuum mechanics null formulation accounts for a fracture process zone and a bulk material while retaining traction continuity across the discontinuity. The additional degre...
Abstract null null This paper focuses on robust null topology optimization null null null for fiber-reinforced composite structures under loading uncertainty. An effective method is presented for simultaneous optimization of fiber angles and structural topology. Specifically, a new parameterization scheme is developed to obtain the continuous spatial variation of fiber angles. The solid isotropic material with penalization method is employed to obtain the material distribution. The null Monte Ca...
Abstract null null null This paper presents an isogeometric formulation of the perfectly matched layer (PML) for time-harmonic acoustic simulations. The new formulation is a null generalization null null of the conventional locally-conformal PML, in which the null NURBS null patch supporting the PML domain is transformed from real space to complex space. This is achieved by complex coordinate stretching, based on a stretching vector field indicating the directions in which incident sound waves a...
#2Eric J. Parish(SNL: Sandia National Laboratories)H-Index: 9
Last. John Tencer(SNL: Sandia National Laboratories)H-Index: 6
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Abstract null null null This work aims to advance computational methods for projection-based reduced-order models (ROMs) of linear time-invariant (LTI) null dynamical systems . For such systems, current practice relies on ROM formulations expressing the state as a rank-1 tensor (i.e., a vector), leading to null null computational kernels null null that are null memory bandwidth null null bound and, therefore, ill-suited for scalable performance on modern architectures. This weakness can be parti...
Abstract null null null null In order to optimally design materials, it is crucial to understand the structure–property relations in the material by analyzing the effect of microstructure parameters on the null macroscopic properties null . In null computational homogenization , the microstructure is thus explicitly modeled inside the macrostructure, leading to a coupled two-scale formulation. Unfortunately, the high computational costs of such multiscale simulations often render the solution of...
Abstract null null null null Recently we have developed the optimal null local truncation error null null method (OLTEM) for null PDEs null null with null constant coefficients null on irregular domains and unfitted Cartesian meshes. However, many important engineering applications include domains with different material null null null null properties null (e.g., different inclusions, multi-material structural components, etc.) for which this technique cannot be directly applied. In the paper OL...
Abstract null null Subcutaneous injection of therapeutic null monoclonal antibodies null null null (mAbs) has recently attracted unprecedented interests in the pharmaceutical industry. The drug transport in the tissue and mechanical response of the tissue after injection are not yet well-understood. We are motivated to study subcutaneous injection using poro-elasticity, including linear and nonlinear poro-elastic models. We first present the fixed-stress split of the null nonlinear model null an...
Abstract null null null null Surrogate models null and adaptive methods can release the huge computational burden of null null structural reliability analysis null . However, it is very difficult to guarantee the accuracy of null uncertainty quantification , especially when noises are contained in samples, which may greatly reduce the confidence of reliability analysis. In this study, we propose a novel Nested Stochastic Kriging (NSK) model method with response noise parameters decoupled from ot...