In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Chat with Us Online Now
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Numerical Approach to Viscoelastic Analysis of Concrete Structures Using Equilibrium and FEM
Author(s): M. Sassone, D. Bigaran, and C. Casalegno
Publication: Special Publication
Appears on pages(s): 21-36
Keywords: computational approach; creep; creep analysis; creep-induced structural effects; design tool; integral equations; structural analysis; viscoelasticity
Abstract:The formulation of creep problems in concrete structures, using linear viscoelasticity leads to integral equations that, generally, can not be solved in closed form. Methods of analysis developed to overcome this problem include the AAEM algebraic method, the method based on the theorems of linear viscoelasticity, or methods that assume simplified creep models. But when the structural problem is complex, involving non-homogeneities, construction steps, changes in static scheme, complex geometry, high prestressing, different materials, a computational approach based on the numerical solution of the systems of equations is required.
Because of the form of the viscoelastic law, in which the present strain is a functional of the whole stress history, the stress history of the structure needs to be stored during calculation. Furthermore the numerical methods necessary to solve the integral equations are not immediately compatible with linear and non-linear finite element analysis and the substitution of integral equations with rate-type approximate laws, seemed to be necessary to allow the use of FEM solvers.
In this paper a set of structural problems is described from the point of view of mathematical and computational formulation, and the general method based on coupling integral equations with the equilibrium method, and then with finite element method, is shown. The proposed formulation allows to perform the step-by-step analysis of any kind of viscoelastic structure, without regard to its complexity, and the computational load, in terms of memory requirements, appears to be no longer prohibitive.
Click here to become an online Journal subscriber