Abstract

This paper deals with topology optimization in plane elastic‐linear problems considering the influence of the self weight in efforts in structural elements. For this purpose it is used a numerical technique called SESO (Smooth ESO), which is based on the procedure for progressive decrease of the inefficient stiffness element contribution at lower stresses until he has no more influence. The SESO is applied with the finite element method and is utilized a triangular finite element and high order. This paper extends the technique SESO for application its self weight where the program, in computing the volume and specific weight, automatically generates a concentrated equivalent force to each node of the element. The evaluation is finalized with the definition of a model of strut‐and‐tie resulting in regions of stress concentration. Examples are presented with optimum topology structures obtaining optimal settings.

Abstract

In this article, the nonlinear constitutive behavior is considered in the geometrically nonlinear formulation for beams proposed by
Simo and Vu-Quoc. The displacement based method is employed in solving the resulting nonlinear problem in the static case. Thermodynamically consistent three-dimensional constitutive laws are used in describing the material behavior, leading to a more precise estimation of the energy dissipated by the structures. The simple mixing rule is also applied in modeling materials which are composed by several simple components. An appropriated cross sectional analysis is implemented under the assumption and limitations of the planarity
of the beam cross sections. Special attention is paid to the development of a method for defining the global damage state of a structure
based on a scalar damage index capable of describing the residual strength and the load carrying capacity. Several numerical examples,
including composite materials and strain localization, are presented and discussed.

Abstract

The purpose of this paper is to develop an improved analytical model for predicting the damage response of multi-storey reinforced concrete frames modelled as an elastic beam-column with two inelastic hinges at its ends. The damage is evaluated in the hinges, using the concentrated damage concepts and a new member damage evaluation method for frame members, which leads to a meaningful global damage index of the structure. A numerical procedure for predicting the damage indices of the structures using matrix structural analysis, plastic theory and continuum damage model is also developed. The method is adequate for the prediction of the failure mechanisms. Using the proposed framework, various numerical examples are included. Based on the obtained results, advantages and limitation of the proposed model are observed. The proposed numerical model is useful to solve multi-storey reinforced concrete frames using a procedure that combines structural finite elements (beams) with moment-curvature constitutive models derived from classic stress-strain ones. It is an inexpensive and reliable procedure to model the frame structures.

Abstract

The paper introduces a new global damage evaluation method which leads to a meaningful global damage index. A numerical procedure for the prediction of local and global damage in civil engineering structures using the finite element method and a continuum damage model, is presented. The method is adequate for the computation of the limit load in reinforced concrete (RC) structures and for the prediction of the failure mechanisms. Details of the applied damage model are given together with a description of the finite element implementation and the procedure for computing the global damage parameters. Examples of applications of the methodology to the nonlinear analysis of a range of RC structures, are presented.

Abstract

Is presented hereby the creation of an optimization software for the design of reinforcing steel for any type of structural elements which may be considered as columns, pillars, pilots or foundation dies, subjected to flexo-compression mechanic stresses for rectangular and circular cross section elements with the support of computational numeric methods and a new mathematical original model named "The idealized steel profile" for the optimization of constructions costs, in which the reinforcing steel is idealized as a steel structural profile embeded in concrete columns, so that then an approxiamte required reinforcing steel area may be determined in order to compute all the possible reinforcing bar options over the element cross section making comparisons in structural efficiency and cost for each option generated to then determine the optimal topology regarding cost and efficiency. The optimization problem is adapted so that it makes the resultant designs practical and convenient for its application in the construction industry in Mexico, based on certain design criteria from the <span style="color: #800000;">NTC-2017</span> (Technical Construction Normative of Mexico City) and questioning other such criteria.

It will be shown how such optimization algorithm was adapted, as well as other general numeric methods for engineering. Moreover the implementation of this program as a software for its practical application in the industry for any concrete structure with "n" number of concrete elements is presented. At the end, results of various experiments with the optimization program are shown, making comparisons between different resultant structural models regarding structural eficciency and geometry.

Abstract

Is presented hereby the creation of an optimization software for the design of reinforcing steel for any type of structural elements which may be considered as columns, pillars, pilots or foundation dies, subjected to flexo-compression mechanic stresses for rectangular and circular cross section elements with the support of computational numeric methods and a new mathematical original model named "The idealized steel profile" for the optimization of constructions costs, in which the reinforcing steel is idealized as a steel structural profile embeded in concrete columns, so that then an approxiamte required reinforcing steel area may be determined in order to compute all the possible reinforcing bar options over the element cross section making comparisons in structural efficiency and cost for each option generated to then determine the optimal topology regarding cost and efficiency. The optimization problem is adapted so that it makes the resultant designs practical and convenient for its application in the construction industry in Mexico, based on certain design criteria from the <span style="color: #800000;">NTC-2017</span> (Technical Construction Normative of Mexico City) and questioning other such criteria.

It will be shown how such optimization algorithm was adapted, as well as other general numeric methods for engineering. Moreover the implementation of this program as a software for its practical application in the industry for any concrete structure with "n" number of concrete elements is presented. At the end, results of various experiments with the optimization program are shown, making comparisons between different resultant structural models regarding structural eficciency and geometry.

Abstract

Often the mere mention of the word “Sustainability” leads to the reflection of the effect of our actions on environment and future generations. Especially the application of reinforced concrete as the most used construction material has a huge impact on a society being sustainable. Thus, the construction industry focuses on the design of environmentally- and resource-friendly buildings. However, due to our aging infrastructure and expected high demand of maintenance and repair in future, a further look on the sustainability of different repair measures for reinforced concrete structures has been neglected in the past. This paper presents a comparative case study of the life-cycle analysis of two different repair measures for reinforced concrete affected by chloride-induced corrosion. The selected repair measures – removal of the chloride-contaminated concrete and cathodic protection – are the most common repair measures in Germany. In future way concrete repair measure could be selected not only by the costs but as well by their environmental impact. This paper provides first information to achieve this target.