Tubular Structures V

its role in

CASE

is rarely to support concrete attract the quality of life of the local people. barrage across the

at the top, at the Detailed of this

is the slab

felt the little structural injuries.

skills their preferred

the main axis of vehicular circulation at called the is the interconnection point of site train, the local railway, as well as the line to the is also hotel automatic

roof roof 2.1 structural Principles taxi rank. divide into different layers of structural elements: the pylons "croissant the "nappe" .oo~

cross bracing planes between each pair of parallel pylon branches portal frame. croissant top serves as the top of the portal must always in tension especially under transverse loads. croissant croissants are 47.5 long vary to to the croissant stiff in the vertical plane flexible out of plane to parasitic temperature effects with the nappe in the longitudinal direction. top chord is naturally in tension other uniform downward loads. It tends to sensitive to load cases of perpendicular to the Also the will tend to buckle. prevent out of plane buckling the extremities of the croissant are braced back to the stiff plane.

to the concrete on the east side to the adjacent roof trusses the west side. masts the trusses are height varies to the roof level. glass plane

to determine the load cases used in the analysis. 2.2.2 supports characteristics of the supports were part of the concrete engineers produced series of increases the tension in the top chord and lateral ties. cases of differential settlements applied based figures the concrete engineering office. Typical load cases were and at the centre concrete at the

to investigate different croissants. vibration the croissants were studied with without amplification factor for the wind. the tensions in the top chord vertical ties of croissant vary considerably under loads, precautions against fatigue had to taken in the

out by as previously described. requirement of in France but unusual in Britain, carry out the final design, including both connections. original reference design, the design of connections, and the submission to the relevant authorities for formal approval. of the complexity of the structure close liaison maintained with the original designers, also with the checking authority site ease of

the welds are positioned the tapered cones and these were carried out the prior to erection. Erection was within the main longitudinal central legs. the base, large steel casting. requirement of the design that articulated capable of resisting uplift. architectural constraint that the to be broken into smaller components for the purposes of transport erection. fabricated as vierendeel girder in lengths to and the ends prepared for site connections. The tie bar top

struts. struts site at their connections to the

pin connections. interface between steelwork glazing contractor takes place at the the via friction welded connection between stainless mild steel. vital feature of the detail is the adjustment

of two pro- tected predicted performance to British design standards and accepted Fire Design methods. are given for testing and designing such girders and specifying their protection. structural Sections, Lattice Girders, Fire Resistance, Fire Design, Fire Tests also have implicit assumptions built into is true of both the British design code, (1990), and the draft steel structures in fire, Sufficient serves of strength are built into the resulting design for- to enable the designer to assess the performance of

to demonstrate act in similar that the design criteria I-section could be applied to lattice girders. in traditional building frame, protection specification application can often be optimised since to strong not to break up and fall into the as each girder failed, ligftt to prevent composite action developing be- slab and girder top chord. 2.1 Deflection criteria are traditional criteria for the failure of

of construction are given in Table of as range of material strength reduction factors accepted that the level is the curate one for use in assessing the behaviour of steel bers fire. the taken as rectly equal to the load ratio to Part states that:

Fire Research tion. resulting load point vertical deflections read using transducers, then checked against computer predictions. In both cases they agreed within Loads were then removed, furnace was then controlled to the standard temperature-time curve given by BSI (1987). 6.1 Girder (tested 4th Little for the first after the top slab cracked transversly position between the loading points. After minutes, further tranverse cracking

then removed preserve the Inspection of the cooled girder confirmed that failure into the test. buckling of outer compression bracing had reduced the outer bays with resulting local plastic distortion of the at three joints consequential failure of the

girders compression bracings had failed higher than the actual values assessed according to (1990). tension bracings had measured tem- peratures substantially higher than critical, they did not fail in Girder only experienced consequential failure in Girder This implies that the methodology of failure Girder centre Bottom Chord 535 538 Inner Bracing 621 Inner

these conclusions, the following simple recom- girder specifying of Present BSI (1990) design procedures can be used assess individual specify a uniform thickness of protection based on the lowest critical temperature taken the with the highest section Factor. resulting tem- perature differentials can be probably be ignored, es- pecially in the half hour fire case.

also because of visible architecture expression sections have an inherent fire resistance of to steel hollow sections to meet severe requirements therefore have to attain significant fire resistance, additional taken, such as: external insulation of the steel

"standard see Fig. Alternative standard in the for Safety, 1991) and for maritime applications Their differences from the ISO-curve are only of no practical significance.

inherent property of the column, but influenced by variety of design parameters. This important, since fire safety requirements for are expressed solely in terms of the fire resistance to attained, and emphasises the need to consider fire resistance requirements the beginning in structural design.

conservative effective length factor (0.7) should be used for assessing the buckling length top floor and for the columns of a building with only one adjacent beam. The higher reduction factor (0.5) structural

application ranges. unfilled SHs-columns Calculation of the concrete comprises of two steps: the determination of the temperature development in the

structural exposed to heated up. The temperature distribution in either unprotected or externally protected, heating behaviour of concrete filled will significantly different. Because of the combination of materials with different heat conductivity, there will be extreme transient heating behaviour. Because of this, concrete filled filled possibilities to

point tu (2/2). concrete have higher load bearing capacity and longer the concrete (better then C20), and the cross sectional dimensions are self activating; self controlling. Natural circulation will be activated heating the water. The density of water than the density of cold water which activates the natural circulation. This

since primarily by the behaviour of connections, is not considered necessary to take additional measures for the protection of connections exposed to fire. If bolted connections are used for insulated steel the bolts as well protected as the This will lead to local increase of insulation thickness.

easily be determined. indicated in Fig. 7, for example, leads provides practical information for unfilled water In addition, in depth recommendations are presented technological aspects and construction edition. (April 1990), Structural fire design of concrete structures, Eurocode 2, Part 10, Luxembourg. of Steel structures, Eurocode 3, Part 1.2: Fire Resistance; Draft 1993-1-2.

Abstract describes. the Flowdrilling and Flowtapping tensile strengths achieved with quality bolts. series of loading tests with types of beam to column join systems both incorporating Flowdrilled holes are described Rolled Hollow Sections (RHS), Flowdrill,

Flowdrill diameter. the base of the thread form the grain flow, see Fig. 2b shows the continuous grain the parent metal into the thread indicative of strong thread design the cold rolling/swaging action of the flowtap tool in cutting of the parent metal takes place.

Abstract to lack of access inside the hollow section has been difficult to practical bolted connection between a W-shape beam and a hollow steel Field welded beam-to-column connections remain the only viable of connecting both elements. Because of of ensuring a dry environment and the concern

(SI, S2 identical except for the fasteners. Details are given in Table 1. larger size with thinner wall was selected for the beam-to-column connections to reveal different behaviour failure of both unstiffened and stiffened flanges. Therefore, the while the flange of stiffened by filling the with concrete. Description of tested specimens

Abstract present. carrying capacity of such connections. The investigations were mainly carried out with respect to different distances of fasteners regarding the failure of hole bearing and failure of net section. results are presented with regard to the parameters loads only have considered. This type of connection especially allows site connections. tubular sections are Saidani and Nethercot (1992). For the construction of medium or long-span trusses of hollow

flange-plate Fig.2. Bolted gusset-plate connection connection

capacity with regard Therefore the end distance the distance between 2.2 Test specimens and implementation in such that either bearing failure or tension failure of plate occur. rectangular hollow sections were 350 long, steel strength grade 10.9 bolts due to with zinc corrosion protection. actual of sections and bolts were measured used

In the evaluations reduced 3.2 Tension failure of plate failure occured in bolt after hole elongation. failure strength following eq. (1) calculated.

values of only. The Fig.7. 4.1 General evaluation method of Eurocode variation coefficients were taken to Wardenier (1992): section width, section depth section thickness to Snijder that the partial safety factor of in Part (11.90) better eq. (3b). Statistical evaluation regarding failure of net section

results can be seen Table 3. Tests with one bolt are considered sufficiently the strength function. Test results with greater end distance are not yet sufficiently covered as well as tests for bolts regard to the fact that the investigations reported

strengh Dipl.-Ing. MUller conducted the Prof. supervised the project. This help gratefully Bijlaard, F.S.K., Sedlacek, Stark, J.W.B. for the determination of design resistance geschraubte Anschllisse an Hohlprofilen. Stahlbau 61, 371-375. section construction with simple bolted connection. Cidect-Programm 6E, Univ. Karlsruhe, 1. Zwischenbericht.

FORMED HEAVY GAUGE

brittle fractured are in the of o. Brittle fracture evaluation

brittle fracture of full scale are less

oc value obtained standard

the case of press formed RHS,the end of which to the weld heat input has to be controlled within an adequate range in order to ensure satisfactory mechanical properties for the joint. toe of the welded connection at the corner of also to

the buckling strength of These should the capacity for stable to severe earthquake loadings. investigates the strength, for the press formed Press formed for the of welded seam. the group of which had one welded seam(specimen No.13, the other those having rest of specimens). further parameter steel plates at the'corner of the section and resulting in welded seams. materials used for press formed and welded were the class steels(JIS 490A). For the roll both class steels(JIS

r: Outside corner radius of stress obtained the straight side of ocr: stress, ecr: strain at ocr ), Bit )'

for specimen No.12 and No.14. III in the rotating jig the welding carried out continuously, the weld toe of the joint finished smoothly.

the average deformation divided the height of specimen. ratio of ocr to that the column manufacturing process:

cyclic bending to absorb the energy of earthquake that cold process ductility for practical use. plasticity also obtained cyclic tests as in Figure the It is

____ j .L LJ:::=t:=r=:c:..--.i...--.J .....--------:--.:..--,

the relationships between and l/a*l/YR,where the material. could be approximated linear function of the products l/a*l/YR. the failure of bending test specimens. failed by local buckling of the flanges fractured from ductile cracks, which had in the welded joint at the corner of the section is considered that cracks occured in the first, rapidly through the wall thickness. Since three of the four fractured specimens locally buckled and broken after attaining the peak of curves, they sufficient ductility. at toes observed

factor for the to be larger than for the vertical is adopted. Figure the macrographs of the profile of these welded joints. this figure, the radius the flank angle e = deg. observed for in the therefore preferable to control the heat input in adequate range or to finish the weld toe smoothly in to prevent the brittle fracture of for the strain concentration in toe, the roll is less other H.(1993). Moreover, the the strength of roll

vertical position) toe (scale of double size) stub column tests cyclic bending tests cold are as follows: strength of can be estimated by the yield linear analysis on stress and strain behavior, to .....

POST-BUCKLING BEHAVIOUR OF COLUMNS - A COMPARISON BETWEEN COLD-FORMED HOT-FINISHED SECTIONS

It is probable that these stub at ultimate

test results for lie b.

little It is clear that

full plastic ),

is in Fig.8 together

is small, for little

COMPRESSED DOUBLE-TUBE MEMBERS the bending resistance. The results obtained from axial loading tests lateral stiffening effect of the inner suitable strength and stiffness prevents buckling of the leads to the axial deformation of the member without any the bending resistance, as shown in feature of this stiffening is that the stiffening member is parallel with the stiffened that the compressive member is stiffened discretely. this paper is to obtain the criterion to Fig.l.

the maximum moment where the stiffness of inner is defined as the yield of the inner tube. Inequality (3) represents the hatched region (hereafter, safe region) in Figure 3. the cross point of

that the plots for specimens A60D, are in the safe region. test setup is in Figure of to the pins which permit the rotation in the vertical plane and the specimen is loaded

section of tubes of which analytical model of at midspan eight to simulate the contact between the the outer tube, the connectors are assumed to the load N - axial deformation u relation as shown in stress - strain curve of the outer tube

result represents the characteristics of double-tubes whether satisfy the criterion or not. the applicability of the are grouped in in which the varied is the EI-series; the other the strength point of the strength and the stiffness of inner tubes for each model plotted as shown in Figure 12(a), which shows that EI3 are on the boundary of the safe region. The results the development of tearing at of the tensile brace

rJ,""' 1---1

P (N)

filled concrete the steel tube (Es)tIs that the

tests buckling tests of

Abstract ficult for are not familiar with the AIJ dations to understand the design formulae. this paper are to investigate the design for the resistance of connections with exterior detail, to explain so that they restrain perfectly the local flexural deformation of tube wall by the out-of-plane force from the beam flanges. In order that tubular connections satisfy the condition of be- resisting connections capable of the ultimate load, the column wall must generally be stiff-

required requirements for the design of strength, welded, resisting connections, rigidly to tubular specifying various connection details as follows: within the at the flange levels (through diaphragms or internal

thickness, flange thickness, constant, those values are under Table in the

the width of the increased the ultimate strength of the connection considerably, but not as as would be suggested by the the design formulae for the load gave an overoptimistic result in almost aJl cases. that they misused the design the expressions were unclear. 2.1 Flange width It is calculate the width of the tapered flange, B'f, exactly from the connection details, because affects the local resistance of connections directly. In 4.4(a) of the recommendation, there of imposed on B'f. details.

angles joints at the circled parts in Fig.3 and necessary, paying attention to the (such as using end tabs) the exterior diaphragm, which is the simplest of stiffening against local failure, extensive studies carried out the local strength of such connections

large diameter-to-thickness ratios of the tensile strengths. for typical connections the difference between the absolute value of compressive and tensile stress in the flanges is not very and the depth of the beam is almost or times the diameter of the is effective to increase the thickness of the at the connection. It is difficult, to restrict local deformation increasing the thickness the range of validity so exterior are usually used except for light

the thickness of the is such that its strength the nominal yield strength of the upper

accurate estimate of the flexural rigidity of butt plate specimens strength exceeds the nominal yield strength of the upper column. The predictive values ob- tained with the flexural rigidity of the butt plate substantially equal. the thickness of the diaphragm plate is set that the strength of the beam-to-column connection exceeds the yield strength of the upper Architectural Institute of Japan for of Structures in

criteria satisfied, but also import- that the connection details can be manufactured cost effectively. After introducing of refined yield line for determining stiffener sizes, con- sideration to the factors influence cost. Initial cost are then included for

enabled yield line to the next depending the location of the line of rotation. These general yield line patterns result in slight rounding of the corners of the inter- action diagram for typical joint detail, as in Fig 4. The present study uses these general forms of

post, the end the post the nodal fabrication cost are the stiffener plate size thickness, the associated cutting, handling Typically the cost of the cutting welding process is related to the time involved multiplied hourly appreciated that considerable of additional work remains to for var- iety of joint types details, with checks the sensitivity to the fabrication times costs, before any final conclusions can be ratio for different stiffener sizes

that the material cost increases as the plate thickness increases, whereas the cutting cost little affected. the welding cost decreases initially as the plate thickness increases from 10 to and then increases as the plate thickness increases to This appar- stiffener stiffener for the nodal joint

described for Space Frame those previously proposed. These mechanisms have been cost optimization study to preliminary that thinner stiffeners are cost effective thicker stiffeners, subject to fully utilising the available weld strength. In this context advantage gained from using truncated diamond stiffeners (Fig

STRUCTURES expert system steel structures. link formulation that the fabricators and designers to estimate the masses costs of the project. or preliminary designs are stored into the the designer has worked for years has used the all the then he will have completed or preliminary designs stored in the of the to use the database-program is to as a library. This is very important the of designs is large. idea in the present study to the databases of the contractor the designer. database of the contractor in the present version is very

the general database program are essential parameters of the problem. need to find out some ways to estimate the price of the project by using the completed stored on the database. important aspect the graphics of the structure authors believed that this kind of expert system for steel serve as a part of the cost-estimation for project. in the study is described in detail in other et al designer

(or even then cannot be carried out although the program is very quick easy to use. this stage of the project the calculation as the source of the database of the expert easy to use and available for micro-computers. building the link the database for the in that the database-program must be easy to use. So, of the done by the final user the program must beforehand using the transfer

A., Paloniemi T., Nevalainen P. design in cad- of the fourth Finnish Mechanics katkaisulaitteelle, thesis, University of Technology, (in Finnish). (in Finnish). Treiberg T. (1987) Pelarfot, Stalbyggnadsinstitutet In

GIRTH WELDS OF TUBULARS WITH AXIAL WALL MISALIGNMENT

INSERTED the tube in particular the non-dimensional parameter D/t. This reduction factor for the load-bearing capacity of such tube-plate connections can be determined. Section, Tube to Plate Connections,

described and the , (-.-----1-

Circular and Rectangular Hollow Section Finite Element Stress Concentration Factor Strain Concentration Factor Para.eters for the load bearing three-plate weld) test defined that could be given to the parametric influence here. Test specimens and testing procedure tests tests evident from the test results that the load- bearing capacity was always below the calculated load- bearing capacity of the tubular sections. static load increased in steps up to the load. After each loading step, the load to the preload the measurements

location of the rosette gauges results axial loading checked the four midlength Usually, the stresses the were within to of the axial stress the eccentricities (e =

evaluation against yielding in the local yielding evaluating the rosette gauges, the direction angles of the principal stresses were important. the point with an elongation of 0.2% (Figure 3). tube geometry expressed by the non-dimensional ratio D/t, to be the governing parameter of the load-bearing capacity. The length of the weld does not play such an imporant role as previously.

load of the (strength depending on design) related to the theoretical yield load of the section ). In two further diagrams (Figures 8 and 9), the ratio load-bearing capacity/theoretical ultimate load section recorded. In the values. In the diagrams 2 and 4 (Figures 7 and 9) a statistical evaluation of results is presented. design is realized inserted plate, the weld and the hollow section are calculated. for the allowable load of the hollow section, a evident from the diagrams that reduction has to since the theoretical yield or load-bearing capacity of the tube cannot be reached. The diagrams represent a first evaluation of tests. to be extended in their range of validity through

experimental and numerical investigations on hollow section connections with inserted for the load-bearing capacity of connections with inserted plates are geometric of the hollow sections. the numerical work, the investigated experimentally have been analysed numerically. Comparisons

Abstract This paper describes the results of series of rectangular hollow section double K-joints (KK-joints) of the multi-planar interaction effects. Analysis, Connections, Double K-Joints, Multi- planar, Rectangular Hollow section, Test. described in this is part of larger

with fen) 1.3 + 0.4 n (bo/bl) S 1.0 negative for compression. 4.1.2 shear criterion, shear formula assumes, depending on the gap bet- bracings, that part of the cross face can accepted that limit, applied load levels, of of the chord depth, be used. this load to with a minimum overall load factor

the actual test load, is higher than this. this reason test are shown in Table 2, the load due to reaching the deformation limit, Fal, and the load attained in the test, 4.1.7 predicted joint failure loads

the recommendations become acceptable. section joints have that the current design the calculation of the capacities of necessary to modify the range of valadity for the bracing to chord with ratio (0.1 /to) to (0.1 O.OlSbo/to), to prevent small bracings being with thin chords. This work has been undertaken within the framework of and

Rectangular Lat Circular Hollow sections. report No.5AS-92/1. List 8.1 Joint geo.etry and .aterial properties of member i - thickness of member i - e angle bracings and chord - yield strength of suffix, bracing, tension bracing loads, and calculated capacities,

-A.-. if initial

is discon- is not I.:,

test set are in Fig.lO. of are listed in 2. tests are dimensionless follows:

test is calculated that the loading position test results sufficiently to the analyses indepen- all is 1.00 the

BACK-TO-BACK DOUBLE CHORD

is outlined in Fig.3. strain strain not exist the of joint is the calculated value of ultirrate

is that the stress, in this condition, equation is given.

in the the bracing yields l:¥ is unyielded. yield is obtained l:¥ the equation.

strain is in the sides to is is to in existing joints.

2.2 Ultimate strength formula for K-joints is large leg of the is is to aT-joint is nearly equal to

in circular hollow sections. in the ultinate strength of in the joint systan is approxirrately presented l:¥ the in Fig .10. in the joint systan estimated l:¥

n-z (,.lIm: ••

usually been conducted excluding modelling of the weld research programme sponsored by Netherlands Technical Foundation) at Delft university of technology for determination of jOints in rectangular and circular hollow sections. includes the weld calibration of the numerical results with of the results of recently completed experimental research in and the Netherlands. participating organisations in the research are Mannesmannrohren A.G, Dusseldorf and Universitat

Joints Joints necessary to establish fixed positions stresses/strains can be measured the hot spot stress /strain calculated. multiplanar KK-joint, stresses are calculated along lines (lines to for each corner of the brace (corners to of the tension brace. Fig. for locations of

uniplanar and the experimental investigation also adopted the quadratic extrapolation for determination of hot spot stress. Fig. limits for of extrapolation. The region of influence of notch stress mini- ----r- strain or stress concentration factor is then obtai- normalising the hot spot strain or stress with the strain or stress defined the of axial, in- plane and out-of-plane strains or stress in the brace

applying Solution for the numerical analyses. :;t:Y

solid elements are used for modelling the joints. All other parts of the girders joints are linear elements rigidly connected to influence is noted the strains in the other joints of the girders. material properties of the numerical identical to those measured for the experimen- of numerical

line in girders 1-4 Joint

strains are in agreement Table 5). For the numerical investigation, stress concentrati- factors are also calculated. ratios are calculated plotted in Fig. average ratio to 1.1, confirms the work on unip1anar joints using

GIRDERS 1,2,3 and 4

dings on braces and chord ends on the and desired locations can be calculated, together with the influence of the unloaded braces. Table shows one typical set of results for joint with and the braces and the chord in the

ry bending moments in the chord of each cases of study. L=~ I 12~1 ~ ~ ~

numerically and experimentally extrapolated average ratio 1.04. calculated numerically of 1.10. Taking this into consideration together with findings from other investigation (van

Part -General Rules and Rules for Buildings. Puthli, R.S. Wardenier, J. Fatigue strength of multiplanar welded, unstiffened hollow section report, Part IV. Stevin report 25-6-89-37/A1, report BI-89-102/63.5.3820. (Confidential) Puthli, R.S. Wardenier, J. Stress and strain concentration factors of multiplanar

STUDY ON THE LOCAL FLEXIBILITY TUBULAR JOINTS EFFECT ON THE STRUCTURAL ANALYSIS OF OFFSHORE PLATFORMS

it is

~IUl· K~60~ 60r\tI

Abstract often constructed at or near ground level and cranes. The number and location of the different the final supports and hence the distribu- tion of forces needs to be considered carefully. to use sup- port points, often with built in height adjustments. these situations, the stability of the is as- sured. In the final position, the effects of the disposition of support points matter of course. A

the support conditions signed the assumed loads. For space frame geometries, essential that the supports are present as potential can traditional square square offset type lacks sional rigidity the are considered as pinned joints. This deficiency is in single Figure General Lift Arrangements for Space

for the calculation of the area of the stable derived :forrrJulae enable designers to effect important parameters such as the yield stress of steel, restraint cross-sectional tasis of opti:I,ization, increasing o:f the enersy-atsorbing cap!:lcity o:f braces. brief survey of selected literature this survey is to sUiu.8rize the ex;)eriiliental results relating to the etable Lyst2resis loop to avoid local buckling. unfortunately, for the D/t or b/t slenderneG3 ratios, in cyclic plastic loading can values. ens proposed 6820/f where is the yield stress is the restraint fector, for pinned 1, is the squash load.

(g)2 obtain )112 -(X-X )1/2] (10) Fig.'. stable hysteresis loop

= 1, 1, 80; sizes in cross-section required D, b

3. (1992) Design of steel structures. ?ert 1.1. brussels, COlliffiittee for Standardization. of Ilietal structures. Chichester. ,J. design of circular tubes loaded

not completely clear the behavior after the ultimate strength of tube-to-tube x- joint in the trusses is reached affects the ultimate be- havior of the truss structure. describes the results of static loading tests circular tubular truss structure with tube-to-tube x- clear effect the ultimate strength of the tube-to-tube x-joint in the truss is affected repeated loads the deformation properties of the joint part. clear the be- havior after the ultimate strength of the joint is reached affects the ultimate behavior of the truss

to four attached to each measurement point. Results and Discussion 3.1 Behavior of the tube-to-tube x-joint solid lines in the Fig. the relationship between the deformation of the tube-to-tube x-joint the bracing

concentration factors can obtained experimentally by the use of of high costs using such determination of based on numerical work together with experimental calibration accepted. From that guidelines for the determination on the basis of numerical finite

deals with results of numerical several aspects regarding the determination. guidelines for determination are given and the influence of the methods of FE-modelling are discussed. considered are: that, for the determination of different methods are applied which cause problems in the interpretation of the test results as well as the results. In the authors' opinion, this to the of recommendations on the determination.

included and defined toe position; using 20-noded solid elements; weld shape included and defined position. toe location and the modelled weld specifications. regarded as the most accurate that ignoring the weld shape leads to entirely different results (especially for the brace Figures and clarify these differences. In these figures, the stress distribution is for the positions (see Figure 1) pertaining to load to determine at fictitious locations without including the weld shape. effect of an element type the that using identical an using an element type without midside-

increases in the length of = 2,0.L Results about analysed for the cases as described in section are given in Figures figures show

Fig. 13. Influence weld shape on for he brace ber. t

reference over the reference brace considered. The values of and while and vary leads to the additional conclusion that increase of especially for the crown positions, also results in larger change of effects

value of and r) between Y-joint and KK-joint.

pin-ended. with chord member ends pin-ended and correction applied introduced in the chord member. conditions. the authors' opinion, correct values of are found influence is present conditions. that for the numerical determination of for chord as well as braces, compensating moment(s) should applied on the chord ends or reanalysing of the

appears that as an to can be determined resolving into according to the principle as explained in Figure 15, in which the contribution of can be neglected. an illustration

the values several guidelines are given in the seperate sections. These approaches are intended to contribute towards uniform of determining stress concentration factors. Appreciation to the Netherlands Technology

K-JOINTS WITH GAP

WELDED

STRENGTH OF PLATE TO CIRCULAR COLUMN CONNECTIONS UNDER MULTIPLANAR AXIAL LOADINGS

(tSubstituting 1/.85 gives e-

LOADED MULTIPLANAR DOUBLE K-JOINTS IN CIRCULAR HOLLOW SECTIONS

HOLLOW SECTION COLUMNS

static ultimate

all the braces are axially in load at the limit is increased to

THREE-DIMENSIONAL T -JOINTS IN RECTANGULAR HOLLOW SECTIONS UNDER BOTH IN-PLANE easily adapted to examine the various effects of different loading conditions and variation in material and properties. Comparisons are in this paper the limited experimental results available for the brace to chord width ratio 0.6, in

resistance capacities below those at which cracking Finite Element Model 25 further study undertaken investigations were undertaken using both and node shells to model the brace and chord elements. to the ability of elements to pick the buckling of the side walls, noded shells have been used

the top face of the chord undertaken, using the model displayed earlier (Figure but the results indirated that its effect strength butt weld with material thickness for subsequent analyses.

are drawn from the results and Multiplanar, Rectangular Hollow Section, K-Joints, Numerical Modelling. the multiplanar interactions the static strength of rectangular hollow section joints. project the steel Construction Institute consists of series of twenty-four multiplanar tests of various configurations which are investigated both ex-

Briefly, the parameters investigated were the brace to chord width the chord width to wall thickness brace wall thickness to chord wall thickness (r) loading regime capable of adequately representing static structural of multiplanar K-joint specimens. Once devel- this in further parametric studies thus cost effectively increasing the database of results on to base design guidance.

choice of deformation deformation measurement on the ultimate failure load to be considered. historically accepted deformation criterion serviceability face deformations should not exceed of the chord width. In multiplanar connec- discovered that kind of deforma- tion limit is also required at ultimate limit state as the post yield portion of the load-deformation curve rising long after the useful capacity of the joint et al. et al. (1993». This deformation limit could be any reasonable

available. This result ultimate load obtained in the uniplanar model was 738kN in comparison with obtained for the multiplanar model. significant conclusions one result but the multiplanar effect does not appear to be significant for using semi-Ioof shell elements