Special Issue on Analysis of Structural Failures Using Numerical Modeling

Abstract

In recent years, there has been a considerable increase in the number of publications related to structural failures in buildings, as shown by the publication of specialized journals, books, and articles, not to mention the proliferation of conferences dealing with the analysis of real cases of structural failure. The importance of studying real cases is based on the need to determine the causes of failure, with the aim, for example, of providing technical assistance to insurance companies in claims cases, designing appropriate repairs, learning from the failure, and consequently preventing recurrences. It should be pointed out here that the study of structural failures has always contributed to progress in thefield of structural design and has encouraged the creation of new theories, concepts, construction details, etc. Numerical modeling, for example, by the finite-element method (FEM), has made the study of structural failures much easier. The calculation programs currently in use can carry out complex processes and have ever more user-friendly interfaces. If we add to this the capacity of existing computers, we can see that the use of complex numerical models is highly appropriate for analyzing failures in actual structures. Being able to carry out nonlinear calculationsmakes it possible to simulate structural behavior until failure occurs or until the structure itself collapses. The possibilities of nonlinear calculations include material yielding and cracking, large displacements, use of intersurface contact areas, and analysis of buckling. This special issue of the Journal of Performance of Constructed Facilities is entitled “Analysis of Structural Failures Using Numerical Modeling” and has its origin in the work of the guest editor in recent years both in his university lectures and in his professional duties as a structural engineer. It contains nine papers that describe the use of numerical models to analyze actual cases of structural failures with the aim of showing the reader how useful the technique can be in analyzing causes and clarifying the failure process. In the first paper, Bartoli and Betti analyze the cracking found to be present in the Capella dei Principi in Florence, Italy, including onsite surveys for subsequent nonlinear FEMmodeling, which make it possible to reproduce the structure’s behavior and thus arrive at the cause of the damage. In the second, Milani and Venturini analyze failure mechanisms in four masonry-built churches by means of numerical modeling with several unique characteristics, such as an analysis of the entire masonry structure, the use of the homogenization technique, and nonlinear behavior. Xu et al. study the progressive collapse of stone arch bridges. Numerical simulation consists of using three-dimensional FEM to perform a nonlinear analysis using contact algorithms in conjunction with the deactivation-element technique. The results obtained predict the actual behavior of stone arch bridges. This paper thus provides reference points for the analysis and prevention of progressive collapse in stone arch bridges. While the first three papers in the special issue deal with the failure of historical masonry structures, the fourth and fifth focus on the failure of masonry walls in two recently constructed buildings. Lourenco and Medeiros describe the failure of a long curved veneer wall, which, shortly after being built, exhibited significant out-of-plane movements, in addition to which part of the wall collapsed during the operation of dismounting sections of veneer. By using FEM, the authors are able to clarify the causes of the collapse and to assist in designing the repair work. In the fifth paper in this special issue, del Coz Diaz et al. use numerical modeling to determine the causes of the collapse of a masonry curtain wall in an industrial building attributable to wind action. An initial model is developed to consider fluid-structure interaction to determine wind loads on the wall. Using the loads obtained from the first model, a simulation of the wall collapse is carried out by FEM. The sixth and seventh papers analyze failures in two metallic structures. Augenti and Parisi analyze the collapse of a long-span steel roof that fell without warning during construction. The authors carry out FEM simulations to determine the causes including the possibility of structural buckling. Fig. 1. Jose M. Adam, Ph.D., Civil Engineer