Performance of Pier-to-Pier Cap Connections of Integral Bridges under Thermal and Seismic Loads

In general, most highway bridges are constructed using prestressed concrete or steel girders. Mechanical joints are provided at the end of each span, to allow for the expansion of the bridge deck due to shrinkage of concrete, thermal effects, and deflections, among others. Smooth riding ability, low noise, wear resistance, and water tightness should be provided by expansion joints. In recent times, the increased traffic volume, along with heavier vehicle movements, adversely affects the performance of expansion joints in the bridge girder, causing a possible failure in one of the above-mentioned mechanisms. The deterioration of the expansion joint may result in leakage of water, concrete cracking, and potential problems in the underlying substructure. In this paper, we study the pier-pier cap connections in integral bridges subjected to thermal and seismic loads using analytical methods and experimental tests.

APPROACH FOR THE AUTOMATED AND DATA-BASED DESIGN OF MECHANICAL JOINTS.

As a result of the increasing challenges in the field of lightweight constructions, the demand for efficient joining technologies is continuously rising. For this purpose, cold forming processes offer an environmental friendly and fast alternative to established joining methods (e.g. welding). However, to ensure a high reliability, not only the selection of an appropriate procedure, but also the dimensioning of the individual joint is essential. While product designers can rely on a wide range of design principles for thermal processes, the dimensioning and evaluation of mechanical joining processes is mainly based on expert knowledge and a few experimental tests. Although few studies already investigated the numerical analysis of mechanical joints, an approach for the sustainable and consistent optimization of the strength and reliability of joining connections for varying use-cases is not available yet. Motivated by this lack, this paper presents an approach for the automated transfer of information within the process chain and the data-based analysis of mechanical joints by using clinching as an example. Therefore, the CRISP-DM reference model is used for the systematic data mining.

Computational efficiency of multi-body systems dynamic models

For several decades, simulation and analysis of mechanisms have been performed with dedicated computer-aided engineering software that implements general dynamic formulations, known in the literature as multi-body systems (MBS) formulations. The MBS name is related to the structure of the mechanism, which is often considered to be a collection of bodies interconnected by mechanical joints (pairs). Nevertheless, only a few formulations are really based on a true multi-body mechanical model, while many others instantiate mathematically quite different mechanical concepts. This paper aims to identify and discuss the mechanical models that fundament the main multi-body mathematical formulations known in the literature. The main features of each model are outlined, based on a detailed presentation of the structure and equations of motion, together with their link with the kinematic and dynamic formulations. A comparative study related to computational efficiency is then presented for the identified main models, based on a test mechanism. Comparative advantages and disadvantages are discussed at the end, considering the identified mechanical models.