Seismic Behaviour and Retrofitting of Timber Frame Walls

2013 ◽  
Vol 778 ◽  
pp. 706-713 ◽  
Author(s):  
Elisa Poletti ◽  
Graca Vasconcelos

Half-timbered buildings are well known as one of the most efficient seismic resistant structure in the world, but their popularity is not only due to their seismic performance, but also to their low cost and the strength they offer. These structures generally consist of exterior masonry walls with timber elements embedded which tie the walls together and internal walls which have a timber frame with masonry infill and act as shear walls. Generally, different types of infill could be applied to half-timbered walls depending on the country, namely brick masonry, rubble masonry, hay, mud, etc. The focus of this paper is to study the seismic behaviour of the walls when no infill is present, i.e. considering only the timber frame, and then compare the results with those of the infill walls. Static cyclic tests have been performed on unreinforced timber frame walls and appropriate strengthening solutions have been applied in order to test the walls in a retrofitted condition, namely (1) steel plates with different configurations and (2) steel flat bars inserted with the NSM technique.

2022 ◽  
Vol 14 (2) ◽  
pp. 651
Author(s):  
Stuart Gee ◽  
Andre Brown

Prefabricated timber component-based systems are the most prevalent industrialised system used to build housing. Along with many other countries, the UK has invested in different types of factory-based prefabrication systems as a means of increasing productivity and enhancing quality. In more recent decades, prefabrication has become part of a series of ‘modern methods of construction’ employed for, and aimed at, delivering sustainable and efficient construction. However, certain pragmatic issues remain. The industry is cyclical, and during periods of declining resources, skills and technical development can be lost. Additionally, factory-based prefabrication requires substantial initial investment and an appropriate local workforce. To help address these issues, this paper presents the concept of an alternative method of production and assembly that takes a different approach to traditional industrialised systems that involve large investments and fixed-location factories. The proposition presented in this paper is that it is possible to design and develop a small, low cost, portable micro-factory that can be taken to a temporary location or construction site, where it can then be used to construct prefabricated closed panels. We describe the development of a working prototype, effectively a micro-factory, along with its potential advantages over a fixed facility.


2013 ◽  
Vol 432 ◽  
pp. 144-151
Author(s):  
Kug Kwan Chang ◽  
Dae Won Seo

Masonry structures are used throughout the world for the construction of residential buildings. However, from a structural viewpoint, the masonry material is characterized by a very low tensile strength; thus, masonry construction often present diffuse fracture patterns. Moreover, masonry bearing and shear walls have been found to be vulnerable to earthquakes. In this study, to improve the seismic performance of masonry structures, hexagonal blocks were developed and six masonry walls used in hexagonal block were tested to failure under reversed cyclic lateral loading. This paper focuses on an experimental investigation of different types of wall used in hexagonal blocks, i.e. walls with different hexagonal blocks and with different reinforcing bar arrangements, subjected to applied cyclic loads. The cracking and damage patterns and hysteretic feature are evaluated. Results showed that damage to blocks in reduced and brittle failure is avoided by the comparatively hexagonal block walls than the existing masonry walls.


2021 ◽  
pp. 088391152199784
Author(s):  
Nipun Jain ◽  
Shashi Singh

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.


Author(s):  
Philipp Andreazza ◽  
Andreas Gericke ◽  
Knuth-Michael Henkel

AbstractArc brazing with low-melting copper-based filler materials, which has long been established and standardized in the thin sheet sector, offers numerous advantages in the processing of predominantly electrolytically galvanized steel structures. In steel and shipbuilding, on the other hand, equipment parts made of thick steel sheets are hot-dip galvanized at low cost and with good corrosion-inhibiting properties. Quality welding of such constructions is not possible without special precautions such as removing the zinc layer and subsequent recoating. With regard to greater plate thicknesses, arc brazing was analyzed in these investigations as an alternative joining method with regard to its suitability for practical use. Within the scope of the investigations, CuSi3Mn, CuMn12Ni2, and four different aluminum bronzes were examined on different sheet surface conditions with regard to the geometrical and production parameters. This was carried out by build-up and connection brazing, executed as butt and cross joints. Quasi-static tensile tests and fatigue tests were used to assess the strength behavior. In addition, metallographic analyses are carried out as well as hardness tests. The suitability for multi-layer brazing and the tendency to distortion were also investigated, as well as the behavior of arc brazed joints under corrosive conditions.


2013 ◽  
Vol 756-759 ◽  
pp. 489-492
Author(s):  
Fu Lu Jin ◽  
Yun Peng Li ◽  
Hong Rui Wang

To automatic test the function and performance of an airborne radar, changeable test adapter is adopted to implement the hardware and software design of the automatic test set of the antenna, transceiver and indicator of the radar based on AT89C52. Problems such as t the different types of interfaces, the various kinds of signals and the test of microwave signal are solved successfully and the objectives of resource sharing and automatic test are realized. The test software is designed by modular structure, and with the help of automatic test set hardware, the required test items of the radar system are experimented and the test process control succeeded. Experiment results show that the automatic test set performs steadily and the results meet the requirements of the airborne radar. The set has the advantages of intelligent, manageable and reducing artificial errors. It provides effective guarantees for radars maintenance, fault diagnosis and fault detection, and has a wide application prospect with low cost.


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