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It would have been inadvisable to revise the content of the standard at the present time, in view of the general approval which hasgreeted its publication, and mainly because of the current discussions on the national basicstandards relating to steel structures DIN 18 ; furthermore, the efforts of ISOITC 96 to achieve an internationally approved ruling with regard to the loads and load combinations which are to be assumed for the verification by calculation of the performance characteristics of cranes, had to be borne in mind.
The principal corrections, including those which have arisen from the processing of the comments received, are described in the Explanatory notes. Field of application Tension members It does not cover craneways, excavators, ropeways, wagon tipples and mining machinery.
Published by Stahlbau-Verlag, Kln. Referred to as high strength friction grip bolts in this standard. The main loads comprise: self weights; loads arising from bulk materials in bins and on continuous conveyors; lifted loads; inertia forces arising from drives; centrifugal forces; impact from bulk material. The additional loads comprise: wind loads; forces arising from skewing; thermal effects; snow loads: loads on walkways, stairways, platforms and hand rails; The special loads comprise: tilting force arising in crane trolleys with positive guidance of the lifted load: buffer forces: test loads.
The above loads are grouped into load cases in clause 5. Table 1. Self weight factors p Travelling speed ZIF, in mimin Runways with rail joints or irregularities road without rail joints or with welded and machined rail joints U p t o 90 Over 90 up to Self weight factor P.
Where several motions corresponding to the load cases listed in table 7 occur simultaneously at different speeds, characterized by different self weight factors p, these factors shall be applied to the respective loads concerned. Trolley travel. The softer the springing of the hoisting gear, the larger the elasticity of the supporting structure, the smaller the actual hoisting speed at the commencement of the hoisting of the useful load, the smaller and steadier the acceleration and deceleration during changes in the hoisting motion, the smaller the factor.
Accordingly, the cranes are classified into lifting classes H 1 , H 2, H 3 and H 4, with different factors p as given in table 2 below. Examples of this are given in subclause Individual self-contained parts of a crane forming integral parts of the complete unit, such as the trolley and the crane bridge or jib, the slewing unit, portal and tower, may be classified into different lifting classes within the limits defined in table 23 for the various types of crane, provided the hoisting conditions are fully known.
Hoisting speed V H Figure 1. Nominal load spectrum factor. Dropping or sudden setting down of useful loads in the case of jib cranes In the case of jib cranes where the dropping or sudden setting down of useful loads represents the usual operating practice, such as for cranes with magnet or grab operation, the resulting inertia force effects shall be taken into account separately.
Instead of adopting a precisely com-. In the case of rope controlled jibs, these negative inertia force effects are limited by the slackening of the ropes, whereby an upward movement of the jib becomes possible. The forces which arise from the subsequent falling back of the jib shall be taken into consideration. In lieu of a more accurate calculation, the quasi-static forces acting on the structure and resulting from the assessment of themovement of thecentreof mass of thesystem underthe effect of the driving forces, of the resistances to motion and of the inertia forces, may be increased by afactor of 1,5 in order to take the dynamic effect into account.
In this respect, loads which are not guided shall be deemed to be rigidly attached to the crane;any swinging of the loads shall be ignored. The adoption of a factor of 1,5 is furthermore. Figure 2. Figure 3. DIN Part 1 Page 5 based on the condition that the driving forces acting on the crane are practically free from backlash. Lateral forces acting in opposite directions arise if a distance Is exists between the centre of the masses to be moved and the resultant of the driving forces.
Where these forces are transmitted through the trackwheels, and where there are more than two wheels per runway side, they shall be uniformly distributed between the outer wheels or outer wheel groups as shown in the examples illustrated in figure 4.
As far as the supporting structure is concerned, e. In the case of wide-span bridge cranes and portal cranes with separate driving mechanisms, whose supporting structures are not designed to compensate for resistances to motion, driving forces and inertia forces, but only for a limited elastic forward motion of one side of the running gear ahead of the other side, special devices shall be provided to ensure that the assumptions on which the design calculation is based are not exceeded.
In cases where there is a considerable amount of play between structural members hereinafter briefly referred to as members which move relatively to one another, for example in the case of the rigid mast and the suspension gear of a stripper crane, a factor larger than 1,5 shall be used. In this connection, one should proceed from the smallest wheel load total in the case of speed-synchronized driven track wheels, or from the sum of the smallest wheel loads in the case of non-speed-synchronized driven track wheels, depending on the type of driving mechanism: the factors mentioned in subclause 4.
The driving forces shall always be distributed among the track wheels in accordance with the type of driving mechanism. The inertia forces during the start-up and braking of cranes shall be entered in the calculation in each case with the trolley in the most unfavourable position for the member being analysed see figure 3.
Where lateral forces due to inertia forces act transversely to the runway, they shall be absorbed by the rails through positive and frictional contact in accordance with the systems adopted for the supporting structure and the running gear, and in accordance with the type of guiding means used.
Unidirectional lateral forces, such as those due to inertia force effects during the start-up and braking of crane. For cranes out of service, the wind load shall be entered in the calculation at the dynamic pressures specified in DIN Part 4. Forces arising from skewing When a crane skews at a skew angle a,a positive contact force S, dependent on the running gear and supporting structure, is generated on the front guiding means or group of guiding means front in the direction of travel ; these guiding means may consist of a wheel flange or of a guide roller, and as a result of force S , a group of forces XI i.
YI i and X2i. Y i which are connected by friction, acting in the 2. The distribution of the force S resulting from the skewing of cranes with flanged track wheels is similar to that described in subclause 4. For cranes with a total of n pairs of track wheels arranged each on an axis i, and of which m are speed-synchronized, and whose wheel loads R I i on side 1 and R2 i o n side 2are of equal magnitude respectively for each side, and assuming the usual tolerances for track wheel diameter, axial parallelism of track wheel bores and position of the runway, with a linearized frictional contact relationship applying equally to longitudinal and transverse slip, the following applies: 4.
Other values of the skew angle a shall be agreed. R is the sum of all wheel loads arising from self weights and lifted load, excluding the factors mentioned in subclause 4. Figure 5. Dimensions and forces due to skewing of a crane with four pairs of track wheels representing different system characteristics 4.
In the case of cranes operating in hot environments, the assumed values shall correspond to the local conditions, e. A linear expansion coefficient in accordance with table 8 shall be entered in the calculations. Pt Figure 6. Example of the distribution of forces due to tilting of a crane trolley with positive guidance of the lifted load in the direction of crane travel 4.
As regards hand rails, a moving horizontal concentrated load acting outwardly or inwardly shall be assumed, amounting to N to allow for persons carrying loads, N to allow for persons not carrying loads.
The above-mentioned concentrated loads need not be taken into account in respect of any member stressed by lifted loads in accordance with subclause 4. For the verification of the buffers and of the strength of the supporting structure, the forces arising from the moving masses of the self weights and of the positively guided lifted loads situated in the most unfavourable position, if applicable, shall be entered in the calculation in each case, but the factors mentioned in subclause 4.
Loads suspended from carrying means and freely oscillating loads need not be considered. An appropriate substitute mass shall be entered in the calculation in lieu of that of the rotating parts of the running gear. The buffer forces shall be distributed in accordance with the buffer characteristics and the possible movements of the supporting structure. In the case of cranes or trolleys with or without useful load, no negative wheel loads may result from 1.
Unless a more accurate stress analysis is carried out, the buffer forces shall be multiplied by an oscillation coefficient in accordance with table 6 for the stress analysis, depending on the shape of the area beneath the buffer characteristic. Table 6. The trolley shall be assumed to be located in the most unfavourable position for this purpose.
Unless a more accurate calculation is made, Ki shall be distributed proportionally between both sides of the craneway without considering any inertia force effects or any skidding of the driven track wheels see figure 6.
If there is an operational possibility of the tilted trolley tilting back again to its normal position due to the sudden yielding of the obstacle, then the forces arising from such an occurrence shall be taken into account.
The buffer forces Pu due to cranes or trolleys crashing against stops or colliding with one another shall be limited by buffers or by similar energy absorbing means. In the case of cranes for which a verification of stability is required in accordance with DIN Part 1 or Part 2, the small and large test loads respectively which are specified in the above-mentioned standards shall be used as the basis for the stress analysis.
In the case of cranes which do not require a verification of stability to be carried out, the test loads are obtained by multiplying the lifted load P by the following factors: small test load: large test load:. Materials other than the steel grades specified in table 8 may be used on condition that their mechanical properties, their chemical composition and if applicable their weldability are guaranteed by the manufacturer of the material concerned.
If the crane is loaded with the small test load, all the permissible motions shall be carried out individually with the load situated in the most unfavourable position; however, due care should be observed during the test. A new motion shall only be initiated after the oscillations arising from the previous motion have ceased completely. If the crane is loaded with the large test load, then the small test load shall first be raised to a short distance from the floor.
Thereafter, the remainder of the load making it up to the large test load shall be attached with all due care, so as to avoid any oscillations if possible. Testing with test load Pk or Pg shall be carried out in the absence of wind. The HVRichtlinien are applicable to high strength bolted joints, see clause 2. Elastic deformations, required for the calculation of statically indeterminate structures for example, shall be determined on the basis of cross-sectional values without any deduction for holes.
In the case of fillet welds subjected to compressive loading in the direction normal to the weld, such as between web plate and flange plate, no allowance shall be made for contact between the members to be joined. All the loads in one column of the zones framed in thick black lines under the heading normal load cases taken together constitute load case H. All the loads in a column under the heading normal load cases taken together constitute load case HZ. In cases whereadditional testsare carried out to determine stresses within the framework of the design loads specified in clauses 4 and 5, the test results may be used as the basis for the calculation, using the same safety factors.
All references to systems, dimensions and cross sections made on drawings shall coincide with those made in the calculations. Deviations are permitted if the safety of all components concerned is increased thereby beyond any doubt. Unless the crane operator has specified anything to the contrary, the calculation shall be made on the assumption Copyright Deutsches Institut Fur Normung E. The individual parts of a member etc. Where in composite members a stress resultant is passed on by a system of welds.
Angle cleats shall be connected with the structure either taking 1 3 times thevalue oftheapplicable proportion of the stress resultant for one leg and the given value itself for the other leg, or taking 1,25 times the value for both legs. Welded-on lug plates shall be connected with the structure taking 1,5 times the value of the applicable proportion of the stress resultant.
Characteristicvalues of steel grades used for the calculation Characteristic values. See DIN Part 2 for selection of quality groups, steelmaking and casting processes of the steels. The height h, related to the top edge of the rail, shall be entered as follows for the purpose of analysing the web: as the distance to the bottom edge of the fillet weld or of the flange boss see figure 7 a ; the fillet weld: as the distance to the centroidal axis of the fillet weld see figure 7 b ; the web rivets: as the distance to the centre line of the rivets see figure 7c.
Dimensions are given in mm. If the rail rests on an elastic support, the transverse and the longitudinal distribution of the bearing pressure under the rail shall be taken into consideration in their most unfavourable pattern in each case for the calculation of the rail bearing beam and of the rail. No such verification need be made for design purposes in respect of subordinate components such as walkways, stairways, platforms, hand rails and cabins.
The overall stresses governed by the type of crane, load case and verification shall not exceed the permissible stresses in each case, and the safety factors shall not be less than the values specified.
In the special cases listed in table 9, the permissible stresses in accordance with tables 10 to 12 may be exceeded, and the factors of safety against bulging may be below those specified in DIN Part 1 and Part 2 and in table Where several special cases occur simultaneously, the total amount of the maximum permissible stresses or the minimum faktors of safetyshall be limited to the greater of the values allowed for one of such special cases, provided however that the percentage allowed for each individual special cases is not exceeded.
Longitudinal stresses shall remain within the permissible stresses in members specified in table The permissible tensile stresses in welds for transverse loading may only be used if the plates requiredforthetransmission of the tensile forces, which are thereby stressed transversely in their rolling plane, are suitable for this purpose see table 24, test method associated with letter symbol D.
DIN 15018-1 (EN - Version 11-1984)