Classical Solid Model Research Articles

A variable kinematic one-dimensional model for the hygro-mechanical analysis of composite materials

An advanced modeling technique for hygro-mechanical analyses has been discussed in the present work. A three-dimensional closed-form solution of the diffusion equation has been developed and used to evaluate the time evolution of the moisture concentration in a composite coupon. A refined kinematic one-dimensional model, derived in the framework of the Carrera unified formulation, has been extended to the hygro-mechanical analysis of composites. The present one-dimensional model has been used to predict the stress evolution in a composite specimen using the moisture concentration, deriving from the analytical solution, as boundary conditions. The results have been compared with those from a solid model derived in by means of the commercial tool Abaqus. The performances of the present approach have been investigated through a convergence analysis. The results demonstrate the numerical efficiency of the present one-dimensional model that can provide a three-dimensional solution with a reduction in the computational cost with respect to the classical solid model.

Multiscale shape–material modeling by composition

We propose a formal framework for modeling multiscale material structures by recursive composition of two-scale material structures. The framework comprises three components: (1) single scale shape–material models, supported by single scale queries, to represent the geometry and spatial distribution of material property on each coarse and fine scales, (2) mechanisms to link the scales by establishing an explicit relationship between shape–material properties at fine scale and material properties at the coarse scale, and (3) multiscale queries abstracting fundamental multiscale operations by recursive composition. While the first component is consistent with classical solid heterogeneous material modeling, the second component manifests itself as a pair of conceptually new upscaling and downscaling functions. We show that classical solid modeling queries, exemplified by point membership testing, distance computation, and material evaluation, generalize to the corresponding multiscale queries that support implicit representations of multiscale structures as a composition of distinct single scale solid material models. The concept of neighborhood is indispensable in all three components. The framework provides a formal and consistent extension of solid modeling framework that underlies most commercial systems in use today, encompasses the variety of different approaches to multiscale modeling, identifies open issues and research problems with existing two-scale modeling methods, and provides foundations for next-generation systems by identifying key objects, classes, representation schemes, and API queries.

Numerical Study about Damping Effect of Liquid Damper on Tall Buildings

Based on the finite element method, three models are built: classical solid model, potential flow model and a combination of fluid-structure coupling model. Based on the above model the damping mechanism of tuned liquid damper has been investigated. Study focused on classical solid model and the boundary constrained potential fluid model respectively. After the completion of the above calculation, the analysis of bidirectional fluid-structure interaction model being carried out with the implicit dynamics algorithm. The results shows the contrast of the dynamic response of structure in the hydrated and anhydrous state. The calculations show that: the additional water mass can effectively reduce the natural vibration frequency of the structure, and it also can effectively reduce the displacement and velocity response of structure under vibration loads.

ε-Topological formulation of tolerant solid modeling

Classical theory of solid modeling relies on the notion of regular sets and presupposes exactness in both geometric data and algorithms. In contrast, modeling, exchange and translation of geometric models in engineering applications usually involve data approximations and algorithms with different numerical precisions. We argue that an appropriate formulation of these geometric modeling problems require finite size neighborhoods, leading to the notion of ε-topological operations. These operations are then used to formulate the definitions of ε-regularity and ε-solid that extend and subsume the corresponding classical concepts as exact special cases. Furthermore, the proposed theory suggests how the classical solid modeling paradigm should be extended in order to deal with the outstanding problems in geometric robustness, validation, and data translation. In particular, it explains why the current methods for validating boundary representaetions are not always sufficient and demonstrates that widely adapted geometric repairs are often unnecessary for maintaining solidity in the presence of numerical inaccuracies.