scholarly journals The effect of concentrated transversal force on the moment resistance of rectangular hollow steel section beams

2019 ◽  
Vol 72 (3) ◽  
pp. 415-423
Author(s):  
Jacqueline Maria Flor ◽  
Ricardo Hallal Fakury ◽  
Rodrigo Barreto Caldas ◽  
Davi Pedrosa de Aguiar
2011 ◽  
Vol 250-253 ◽  
pp. 1271-1274
Author(s):  
Saggaff Anis ◽  
M.Md. Tahir ◽  
Arizu Sulaiman ◽  
Poi Ngian Shek ◽  
Cher Siang Tan ◽  
...  

The objective of this paper is to present the behaviour of composite beam using Trapezoid Web Profiled (TWP) steel section by determining the moment resistance and the deflection of the beam with composite and non-composite connections. The TWP steel section is a built up section where the flange is of S355 steel section and the corrugated web of S275 steel section. Three full scales testing setting-up as sub-assemblage frame have been carried out. It was concluded that the use of composite connection and extended end-plate has reduced significantly the deflection and has significantly increased the loading capacity of composite beam.


Author(s):  
Alexander Plakhov ◽  
Tatiana Tchemisova ◽  
Paulo Gouveia

We study the Magnus effect: deflection of the trajectory of a spinning body moving in a gas. It is well known that in rarefied gases, the inverse Magnus effect takes place, which means that the transversal component of the force acting on the body has opposite signs in sparse and relatively dense gases. The existing works derive the inverse effect from non-elastic interaction of gas particles with the body. We propose another (complementary) mechanism of creating the transversal force owing to multiple collisions of particles in cavities of the body surface. We limit ourselves to the two-dimensional case of a rough disc moving through a zero-temperature medium on the plane, where reflections of the particles from the body are elastic and mutual interaction of the particles is neglected. We represent the force acting on the disc and the moment of this force as functionals depending on ‘shape of the roughness’, and determine the set of all admissible forces. The disc trajectory is determined for several simple cases. The study is made by means of billiard theory, Monge–Kantorovich optimal mass transport and by numerical methods.


2015 ◽  
Vol 802 ◽  
pp. 237-242
Author(s):  
Jin Ying Ling ◽  
Fatimah De’nan

This paper presents a numerical investigation on the effect of perforation to the steel purlin on bending behaviour. In order to reduce the weight of steel sections, web profile with openings has been introduced in the construction industry, so does the purlin. However, there is no research done on the C-purlin with perforation. Hence, 33 nonlinear analyses were carried out to investigate effect of perforations to the steel purlin on bending behaviour. Yield moment of the steel purlin with and without perforation will be determined. And, effect of various perforation shapes and size on bending behaviour is investigated. Finite element model was developed using software LUSAS. C-channel steel section without opening is used as a control specimen. The results are expressed in term of yield moment. The results show that the edge distance from the opening to the support plays an important role in affecting the moment capacity of C-purlin. Increasing the opening spacing would increase the moment capacity. Number of openings also affects the moment capacity of the section. Octagonal shape with 0.40H and e= 350 mm shows the highest yield moment value with 16.318% higher than that of section without opening. In conclusion, perforation increases the moment capacity of the C-steel purlin.


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Muhammad Firdaus ◽  
Anis Saggaff ◽  
Mahmood Md Tahir ◽  
Kiagus Muhammad Aminuddin ◽  
Shek Poi Ngian ◽  
...  

The use of cold-formed steel (CFS) as part of a major construction has been rapidly increasing recently, as it is considered viable as an alternative to the conventional hot-rolled steel section. However, information about CFS as part of a non-composite system is still limited as the connection is designed as a pinned connection, only good for roof trusses and wall paneling. The aim of this research is to propose a connection for CFS sections that could enhance the strength of typical CFS connections, from pinned to partial strength connections. This paper presents the behavior of the partial strength of a non-composite beam-to-column connection for a cold-formed steel section where a gusset plate was used as a stiffener. This type of proposed connection for CFS is not limited only to the construction of roof trusses and wall cladding, but is also able to provide better flexural strength in semi-continuous construction. The proposed connections consisted of 6 specimens divided into two types, the first of which were stiffened by the gusset plate and the second of which were enhanced further with the top, seat and web angles. From the results of the experimental tests it was concluded that all the proposed connections can be categorized as partial strength connections, where the strength was more than 25% of the connected beam and suitable for use in semi-continuous construction. A relatively good agreement was recorded for the comparison between the experimental results and the predicted results from the EC3 component method super-imposed with a haunched gusset plate and top, seat and web angle components, which differed in the range of 1.31 to 1.5 times for the moment resistance and 1.07 to 1.37 times for the stiffness of the proposed connections.


2018 ◽  
Vol 7 (4.35) ◽  
pp. 668
Author(s):  
Rahima Ummi Kulsum Nadya ◽  
Fathoni Usman

A beam-column connection of cold-formed steel section was arranged as an isolated joint. An experimental testing has been done on the model specimen until the model reached its failure mode. The behaviour of the cold-formed bolted connection in the matter of its strength and stiffness of the steel connection was studied. In this study, gusset-plate and bolted angle flange cleat connection were used in which it can stiffen the cold-formed beam-column connection. Moment-rotation curves were generated from the test results to represent the behaviour of the bolted connections. The design expression of the beam-column connection is following the design standard of Eurocode 3 BS EN 1993-1-8. The set-up of the experimental analysis, the procedure and the failure mode results are discussed in details. The moment capacity of 5.9 kN.m has been recorded for the beam section and 7.3 kN.m for the column section. The stiffness (Sj) was recorded as 120.94 kN.m/rad for the beam section and 182.42 kN.m/rad for the column section.


Author(s):  
A. V. Crewe

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.


Author(s):  
Burton B. Silver

Sectioned tissue rarely indicates evidence of what is probably a highly dynamic state of activity in mitochondria which have been reported to undergo a variety of movements such as streaming, divisions and coalescence. Recently, mitochondria from the rat anterior pituitary have been fixed in a variety of configurations which suggest that conformational changes were occurring at the moment of fixation. Pinocytotic-like vacuoles which may be taking in or expelling materials from the surrounding cell medium, appear to be forming in some of the mitochondria. In some cases, pores extend into the matrix of the mitochondria. In other forms, the remains of what seems to be pinched off vacuoles are evident in the mitochondrial interior. Dense materials, resembling secretory droplets, appear at the junction of the pores and the cytoplasm. The droplets are similar to the secretory materials commonly identified in electron micrographs of the anterior pituitary.


Author(s):  
J. S. Wall

The forte of the Scanning transmission Electron Microscope (STEM) is high resolution imaging with high contrast on thin specimens, as demonstrated by visualization of single heavy atoms. of equal importance for biology is the efficient utilization of all available signals, permitting low dose imaging of unstained single molecules such as DNA.Our work at Brookhaven has concentrated on: 1) design and construction of instruments optimized for a narrow range of biological applications and 2) use of such instruments in a very active user/collaborator program. Therefore our program is highly interactive with a strong emphasis on producing results which are interpretable with a high level of confidence.The major challenge we face at the moment is specimen preparation. The resolution of the STEM is better than 2.5 A, but measurements of resolution vs. dose level off at a resolution of 20 A at a dose of 10 el/A2 on a well-behaved biological specimen such as TMV (tobacco mosaic virus). To track down this problem we are examining all aspects of specimen preparation: purification of biological material, deposition on the thin film substrate, washing, fast freezing and freeze drying. As we attempt to improve our equipment/technique, we use image analysis of TMV internal controls included in all STEM samples as a monitor sensitive enough to detect even a few percent improvement. For delicate specimens, carbon films can be very harsh-leading to disruption of the sample. Therefore we are developing conducting polymer films as alternative substrates, as described elsewhere in these Proceedings. For specimen preparation studies, we have identified (from our user/collaborator program ) a variety of “canary” specimens, each uniquely sensitive to one particular aspect of sample preparation, so we can attempt to separate the variables involved.


Author(s):  
Oscar D. Guillamondegui

Traumatic brain injury (TBI) is a serious epidemic in the United States. It affects patients of all ages, race, and socioeconomic status (SES). The current care of these patients typically manifests after sequelae have been identified after discharge from the hospital, long after the inciting event. The purpose of this article is to introduce the concept of identification and management of the TBI patient from the moment of injury through long-term care as a multidisciplinary approach. By promoting an awareness of the issues that develop around the acutely injured brain and linking them to long-term outcomes, the trauma team can initiate care early to alter the effect on the patient, family, and community. Hopefully, by describing the care afforded at a trauma center and by a multidisciplinary team, we can bring a better understanding to the armamentarium of methods utilized to treat the difficult population of TBI patients.


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