An Enhanced Finite Element Macro-Model for the Realistic Simulation of Localized Cracks in Masonry Structures: A Large-Scale Application

ABSTRACT

Finite element macro-modeling approaches are widely used for the analysis of large-scale masonry structures. Despite their efficiency, they still face two important challenges: the realistic representation of damage and a reasonable independency of the numerical results to the used discretization. In this work, the classical smeared crack approach is enhanced with a crack-tracking algorithm, originating from the analysis of localized cracking in quasi-brittle materials. The proposed algorithm is for the first time applied to a large-scale wall exhibiting multiple shear and flexural cracking. Discussion covers structural aspects, as the response of the structure under different assumptions regarding the floor rigidity, but also numerical issues, commonly overlooked in the simulation of large structures, such the mesh-dependency of the numerical results.     

“乾隆大阅甲”的保护处理

“乾隆大阅甲”与常见的织绣品相比,在所用材料和制作工艺上有其特殊性,处理起来难度较大。作者通过反复的摸索和试验,解决了用树脂丝网加固“乾隆大阅甲”过程中所遇到的一系列问题,处理后的效果令人满意。另外,本文对今后工作的研究方向作了有益的探讨。     

Hobbes ou la crise de l'état baroque

Thomas Hobbes in Leviathan presented a paradigm of the social contract that has proven foundational in Western political thought. A proper understanding of the philosopher’s thought is thus of paramount importance. I argue that today’s case for a religiously tolerant Hobbes has missed an important part of the historical record. I first consider an obscure but important document, the second edition of the Humble Proposals. It demonstrates that leading members of a seventeenth century Christian denomination, the Independents, considered a state-enforced confession of faith. Independents are generally seen as tolerant, and one of the arguments for Hobbesian toleration is that Hobbes endorsed them. But the second edition of the Humble Proposals aligns with the possibility in Hobbes that the civil sovereign will impose part III of Leviathan on the Universities and treat its contents as a legally required confession of faith – one that may be necessary for security, and the avoidance of civil war. Hobbes’s endorsement of Independency alone cannot be used to argue that his work leads to religious toleration. The evidence I present reinforces an earlier assessment and alongside other evidence points to the return of the intolerant Hobbes.     

The influence of screen mesh size,and size and shape of rodent teeth on recovery

It is suggested with increasing frequency that rather than the industry standard of 1/4 inch mesh, zooarchaeologists use 1/8 inch or even 1/16 inch mesh to insure more complete recovery. These suggestions are based on the implicit assumption that the body size of a taxon and the probability that the remains of that taxon will be recovered are positively correlated. Size of skeletal specimens provides a more direct measure of recovery probability and accounts for the fact that not all skeletal elements in a body are the same size. Frequencies of eight kinds of rodent teeth representing three genera recovered from the Marmes archaeological site in southeastern Washington State, USA, correlate strongly with tooth size despite the use of 1/25 inch mesh screens. Shape of tooth types measured is insufficiently varied to reveal more than a general relationship between shape and recovery frequency. Choice of an appropriate screen mesh should consider the nature of a deposit, research goals, and cost efficiency.     

Toward Hybrid Modeling and Automatic Planimetry for Graphic Documentation of the Archaeological Heritage: The Cortina Family Pantheon in the Cemetery of Valencia

ABSTRACT

The current trend toward the hybrid methodology of combining terrestrial laser scanner (TLS) with close-range and UAV-assisted photogrammetry is becoming the most effective method for the complete capture of archaeological sites. In this article, we consider three objectives in this regard: first, to check an integration procedure, based on different capture techniques, to obtain the best possible complete digital model in different situations related to size, lighting, and occlusions. Second, a “laser scanning with the help of photogrammetry” strategy for the operation with the different data sources, which allows to adapt the processes of photogrammetric orientation, cloud registration, and automatic texturing, to the characteristics of each capture model. Finally, to present the digital edition of these models through automatic technical projections and realistic visualizations, to show their ability to interpret their geometry or share their knowledge, respectively.