The strength of fillet welds under longitudinal and transverse shear: a paradox

1985 ◽  
Vol 12 (1) ◽  
pp. 226-231 ◽  
Author(s):  
D. J. Laurie Kennedy ◽  
Gary J. Kriviak
Keyword(s):  
Longitudinal Direction ◽  
Longitudinal Axis ◽  
Fillet Welds ◽  
Strength Analysis ◽  
Design Standards ◽  
Transverse Strength ◽  
Strength Based ◽  
Current Design ◽  
Longitudinal Strength ◽  
Vector Sum

Fillet welds loaded only by transverse forces exhibit considerably greater strength than those loaded only by longitudinal forces. Current design standards in North America generally base the strength on the minimum value obtained in the longitudinal direction and consider that the strength is independent of the direction of loading. These standards require as well, that fillet welds loaded simultaneously by both longitudinal and transverse components be designed such that the vector sum of the components does not exceed the longitudinal strength. Experimental data, although limited, indicate that this vector approach is very conservative. Some standards do allow an ultimate strength analysis, although the method is not given. The transverse strength of fillet welds is about 1.45 times the longitudinal strength, and for angles of loading of up to 45° from the longitudinal axis, welds with transverse components have longitudinal capacities in excess of the longitudinal strength. Based on available test data, two alternative interaction relationships are proposed for the design of fillet welds loaded simultaneously by longitudinal and transverse forces. Key words: connections, design, fillet welds, longitudinal strength, transverse strength, steel.

Fatigue Capacity of Load Carrying Fillet-Welded Connections Subjected to Axial and Shear Loading

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Inge Lotsberg
Keyword(s):  
Axial Loading ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Shear Loading ◽  
Fillet Welds ◽  
Strength Analysis ◽  
Load Carrying ◽  
Eurocode 3 ◽  
The Status ◽  
Current Design

The status on current design recommendations concerning the fatigue capacity of load carrying fillet welds was presented by Maddox (Maddox, S., 2006, “Status Review on Fatigue Performance of Fillet Welds,” Proceedings of the OMAE Conference, Hamburg, Germany, Jun., Paper No. OMAE2006-92314) based on a literature survey. In order to examine the validity of the recommendations and to supplement the fatigue test database, a test matrix with 33 specimens was developed. This included 8 simple fillet-welded cruciform joints that were subjected to axial loading and 25 fillet-welded tubular specimens that were subjected to axial load and/or torsion for simulation of a combined stress condition in the fillet weld. The data obtained from these fatigue tests are presented in this paper. The test data are also compared with design guidance from IIW (1996, Fatigue Design of Welded Joints and Components: Recommendations of IIW Joint Working Group XIII-XV, A. Hobbacher, ed., Abington Publishing, Cambridge), Eurocode 3 (1993, Eurocode 3: Design of Steel Structures—Part 1–1: General Rules and Rules for Buildings), and DNV-RP-C203 (DNV, 2005, DNV-RP-C203, Fatigue Strength Analysis of Offshore Steel Structures).

Ultimate strength of fillet welded connections loaded in plane

1990 ◽  
Vol 17 (1) ◽  
pp. 55-67 ◽  
Author(s):  
Dale F. Lesik ◽  
D. J. Laurie Kennedy
Keyword(s):  
Ultimate Strength ◽  
Statistical Data ◽  
Fillet Welds ◽  
Test Results ◽  
Full Scale Test ◽  
Design Standards ◽  
Limit States ◽  
Safety Design ◽  
Current Design ◽  
Scale Test

Fillet welded connections are frequently loaded eccentrically in shear with the externally applied load in the same plane as the weld group. While some current design tables are based on ultimate strengths, methods of analysis that incorrectly mix inelastic and elastic approaches are still used. These methods give conservative and variable margins of safety. Design standards generally use a lower-bound approach basing strengths on the longitudinal value neglecting, conservatively, the increase in strength for other directions of loading. The factored resistance of fillet welds, as a function of the direction of loading, is established based on ultimate strength expressions developed herein and using geometric, material variations, and test-to-predicted ratios reported in the literature. Factored resistances of eccentrically loaded fillet weld groups are established. These are basesd on the method of instantaneous centres, ultimate strengths, and the load–deformation expressions developed herein that are functions of the angle of loading. Also, statistical data on geometry, material variations, and the comparison of predicted strengths with the full-scale test results of others are used. Tables of design coefficients giving factored resistances for various eccentrically loaded fillet welded connections are developed. The coefficients, on the average, are essentially the same as those in current design tables. Key words: connections, design tables, eccentric, fillet welds, limit states, ultimate strength.

GENERAL METHOD FOR CALCULATING BUTT AND ANGLE WELDS FOR STRENGTH

2021 ◽  
pp. 28-33
Author(s):  
Yu. N. Vavilov ◽  
I. Yu. Skobeleva ◽  
I. A. Shirshova
Keyword(s):  
Calculation Method ◽  
Calculation Scheme ◽  
Calculation Procedure ◽  
Fillet Welds ◽  
Specific Design ◽  
Strength Of Materials ◽  
Butt Welds ◽  
Strength Based ◽  
Design Solutions ◽  
General Method

The existing methods for calculating butt and fillet welds are private, developed for specific design solutions that do not take into account the variety of weld shapes and the variety of combinations of forces and moments. The article provides a general method for calculating butt and fillet welds for strength, based on the calculation method for nominal stresses, adopted in the strength of materials. This technique was used without any changes for the calculation of butt welds, since the weld is an extension of the part. The calculation of fillet welds is based on two assumptions, on the basis of which a calculation scheme has been developed, which makes it possible to use the calculation method for rated stresses. The article proposes two design schemes, considers the calculation procedure and derives two generalized strength conditions for the verification calculation of butt and fillet welds.

Nature of the mammalian ciliary metachronal wave

1993 ◽  
Vol 75 (1) ◽  
pp. 458-467 ◽  
Author(s):  
L. B. Wong ◽  
I. F. Miller ◽  
D. B. Yeates
Keyword(s):  
Beat Frequency ◽  
Longitudinal Direction ◽  
Longitudinal Axis ◽  
Ciliary Beat Frequency ◽  
Metachronal Wave ◽  
Epithelial Tissues ◽  
Tracheal Epithelial ◽  
The Mean ◽  
Temporal And Spatial ◽  
Ciliary Beat

The temporal and spatial coordination of ciliary beat (metachronicity) is fundamental to effective mucociliary transport. Metachronal wave period (MWP) and ciliary beat frequency (CBF) of fresh excised sheep and canine tracheal epithelial tissues were measured with the use of a newly developed alternating focal spot laser light scattering system. MWP was determined from cross correlation of the heterodyne signals from the alternating focal spots. CBF was determined by autocorrelation of the heterodyne signals from each of the spots. MWP and CBF were measured in four sheep tracheal epithelial tissues with the use of longitudinal interfocal spot distances of 6 and 18 microns. In three canine tracheal epithelial tissues MWP and CBF were measured both longitudinally and circumferentially with interfocal spot distances of 5, 15, 65, 87, and 96 microns. For the sheep tracheal epithelial tissues the mean CBF was 5.9 +/- 0.4 Hz (mean of means; range 3.6 +/- 0.5 to 9.9 +/- 1.5 Hz), whereas the mean MWPs for 6- and 18-microns interfocal spot distances were 0.50 +/- 0.1 and 0.47 +/- 0.1 s, respectively. For the canine tracheal epithelial tissues the mean CBF was 4.0 +/- 0.2 Hz (2.0 +/- 0.8 to 7.2 +/- 3.2 Hz), whereas the mean longitudinal MWP was 1.5 s and the mean circumferential MWP was 2.1 s. Geometric combination of the MWP components leads to a derived MWP of 2.6 s with a propagation direction of 54 degrees with respect to the longitudinal axis of the trachea. MWP was found to be episode modulated with 12- to 20-min intervals in the longitudinal direction, but modulation was not as apparent in the circumferential direction. These data suggest that MWP and CBF are regulated by separate intracellular, intercellular, and intraciliary mechanisms.

scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

Longitudinal Strength Analysis of the Grounded Barge Carrying Independent Cargo Tanks

1972 ◽  
Vol 9 (03) ◽  
pp. 333-344
Author(s):  
Finn C. Michelsen ◽  
Uilmann Kilgore
Keyword(s):  
Operational Calculus ◽  
Beam Theory ◽  
Class Ii ◽  
Class I ◽  
Strength Analysis ◽  
Bending Moments ◽  
Bernoulli Beam ◽  
Method Of Solution ◽  
Longitudinal Strength ◽  
Euler Bernoulli Beam

The problem has been treated of determining deflections and bending moments of the barge hull and independent cargo tanks combination as these occur in Class I and Class II barges during grounding. The method of solution is that of the initial parameters, which is here developed by means of operational calculus. The solution is closed and exact within the limitations of the Euler-Bernoulli beam theory.

Comparative Study of Cyclic and Shake Table Tests for Simple for Dead Load and Continuous for Live Load Steel Bridge System in Seismic Area

2020 ◽  
Vol 2674 (7) ◽  
pp. 233-243
Author(s):  
Amir Sadeghnejad ◽  
Sheharyar Rehmat ◽  
Islam M. Mantawy ◽  
Atorod Azizinamini
Keyword(s):  
Plastic Hinge ◽  
Longitudinal Direction ◽  
System Level ◽  
Live Load ◽  
Shake Table ◽  
Steel Bridge ◽  
Dead Load ◽  
Design Standards ◽  
Component Level ◽  
Bridge System

A new superstructure to pier connection for simple for dead load and continuous for live load (SDCL) steel bridge system in seismic areas was developed. As proof of concept, component level and system level tests were carried out on scale models. The component test was conducted under cyclic loading and the results showed satisfactory performance conforming to design standards. The same detail was incorporated in a system level shake table testing which was subjected to bidirectional earthquake excitations. The results showed that the connection behaved well under high levels of drift and acceleration. The capacity protected elements sustained minimal damage and the plastic hinge was limited to a predefined location in the column. In this paper, a summary of results from both tests is presented and compared. The results showed that the SDCL components remained within the elastic range. It was concluded that the dowel bars in the cap beam are the main load-carrying elements under excitations in the longitudinal direction of the bridge and the provisions of current design codes are adequate for the design of these reinforcing bars. Both test protocols showed similar behavior despite the differences in construction methods and material properties.

Intersection Design and Decision–Reaction Time for Older Drivers

1997 ◽  
Vol 1573 (1) ◽  
pp. 68-71 ◽  
Author(s):  
David W. Naylor ◽  
Johnny R. Graham
Keyword(s):  
Reaction Time ◽  
Reaction Times ◽  
Older Drivers ◽  
Design Standards ◽  
Older Driver ◽  
The Past ◽  
Sight Distance ◽  
Stop Sign ◽  
Current Design ◽  
Design Value

Trends in automobile and roadway use have changed drastically over the past several years. Changes in the trends include an increase in the percentage of licensed drivers, annual miles driven, and an increase in the number of older drivers. Of particular concern is the increase in the number of older drivers and the question of whether the current design standards adequately meet the needs of the older driver. In this study, the perception-reaction time variable used in calculating intersection sight distance at stop sign-controlled intersections was evaluated. The current design value for the perception–reaction time is 2.0 sec, which has been used since the 1940s when the driving population was much younger. A field experiment was performed to determine an appropriate value for today’s driving population. Subjects were covertly videotaped as they entered two rural and two urban stop sign-controlled interactions. Mean decision–reaction times were determined for an older and a younger group of subjects. The older group, consisting of 104 subjects, averaged 69.3 years of age and had a mean decision–reaction time of 1.32 sec. A group of 104 younger subjects, less than 30 years of age, had a mean decision–reaction time of 1.24 sec. The 85th percentile decision–reaction time for the older group was 1.86 sec and for the younger group, 1.66 sec. Both times were less than the current AASHTO design value of 2.0 sec.

Proposal of Fatigue Life Equations for Carbon and Low-Alloy Steels and Austenitic Stainless Steels as a Function of Tensile Strength

2013 ◽  
Author(s):  
Hiroshi Kanasaki ◽  
Makoto Higuchi ◽  
Seiji Asada ◽  
Munehiro Yasuda ◽  
Takehiko Sera
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Stainless Steels ◽  
Room Temperature ◽  
Austenitic Stainless Steels ◽  
Low Alloy Steels ◽  
Strength Based ◽  
Fatigue Data ◽  
Current Design ◽  
Alloy Steels

Fatigue life equations for carbon & low-alloy steels and also austenitic stainless steels are proposed as a function of their tensile strength based on large number of fatigue data tested in air at RT to high temperature. The proposed equations give a very good estimation of fatigue life for the steels of varying tensile strength. These results indicate that the current design fatigue curves may be overly conservative at the tensile strength level of 550 MPa for carbon & low-alloy steels. As for austenitic stainless steels, the proposed fatigue life equation is applicable at room temperature to 430 °C and gives more accurate prediction compared to the previously proposed equation which is not function of temperature and tensile strength.

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