FEM 9.311

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Page 4 FEM 9.311Table 3. Friction force coefficient f as depending on the angle of skew 0:0: 0/00 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 6.0 7.0 8.0 9.0 10.0 15.0f 0.035 0.066 0.094 0.118 0.139 0.158 0.175 0.190 0.203 0.214 0.233 0.248 0.259 0.268 0.275 0.300S = f . R st8t(force due to running askew)2.3 Categories of special loadswhere:O:FO:vwheel load due to deadloads and lifted loadwithout the' coefficients according to sections2.1.3 and 2.1.4, ~oO:F + ~v + 0: 0 + O:s _' 10 looangle of skew in relation to the spacing of the guidemembers which give rise to the frictional forces, thesum total of all possible misalignments transverse tothe runway when the SiR machine takes up a skewedposition.angle of s~ew due to the clearance between straightrail and form grip guide members, i. e. at least5 mm for wheel flanges and 3 mm for guide rollers.angle of skew due to wear. At least 1.5 % of the railhead width in the case of guide rollers and at least5 % of the rail head width in the case of wheel" flanges.0: 0 ~ 1 °iot, angle of skew due to SIR machine tolerances2.3.1 Buffer forcesFor this special case of loading'it is assLimed that duringregular service collisions of SiR machines do not occur.The buffer forces Fp, which occur when SIR machinesimpact against runway stops, shall be limited by providingadequ!lte buffers or similar means of dissipatingenergy. The required working capacity for energy dissipationand the maximum,buffer forces Fp shall bedetermined for SIR machines on the basis of 100 %nominal travel speed., If automatic means 2) ensure a reduction of the travelspeed; the required working capacity of the buffers forenergy dissipation and the maximum buffer forces Fpmay be calculated taking the then fastest possible travelspeed, but at least 70 % of the nominal speed, as a basis.The kinetic energy shall be assumed to be'm x v2Wkin = 2O:s ~ 1 0/00 angle of skewdue to tolerances of the raillaid on the floor2.2.2 Temperature effectsTemperature effects must be taken into considerationonly in special cases. Based on an assumed temperatureof + 10 °C during erection, variations in temperatureof ± 35 K or, in the case of an uneven temperature risein individual sub-assemblies, variations of ±15 K shallbe assumed for an SIR machine operating in an openbuilding.These values must be adequate for local conditions inthe case of SiR machines operating in plants with a hotatmosphere or in low-temperature warehouses.A coefficient of elongationO:t = 12 ',10- 6 mm/mm xK (for steel)shall be used for the calculations.2.2.3 Loads on platforms and handrailsIn addition to the deadloads, a single live load shall beassumed for platforms, i. e.300 kg for persons walking on it and carrying a load150 kg for persons walking on it without a load.A concentrated live load applied horizontally to the outsideor to the inside shall be assumed for handrails, i. e.30 kg for persons carrying a load and15 kg for persons without a load.These concentrated loads need not be taken into accountin the case of structural members subjected to loadslifted according to section 2.1.2.For an analysis of the buffers and the strength of thestructure the forces due to the moving masses of thedeadloads and of the guided lifted loads 3) shall beassumed to be effective in their respective least favourableposition, but without the coefficients according tosections 2.1.3 and 2.1.4.'A corresponding equivalent mass has tobe introducedinto the calculation for rotating parts of the travelmechanism. The buffer forces shall be distributedaccording to the buffer characteristics and the freedomof movement of the structure.If energy converting buffers are provided, an amount of10 % may be deducted from the total energy for thefree dying down of structure oscillations.In the case of a simplified analysis of the stresses in thestructure,the' buffer end forces shall be multiplied byan oscillation coefficient selected from table 4 inaccordance with the shape and area below the buffercharacteristic.Table 4.Oscillation coefficients for simplifiedcalculationThe area below the buffer Oscillation coefficientcharacteristic resembles Sp at SiR machineapprox.impactTriangle 1.25Rectangle 1.50,2) In the case of electric means at least 2 safety devices shall' be provided which monitor each other.3) The maximum possible friction force between load unit and load handling accessory shall be assumed for the load unit as a nonguidedlifted load.
FEM 9.311 Page 5The travel wheels of SiR machines with or without apayload shall not lift off the rail due to the 110 % bufferforce and the above-mentioned deadloads and liftedloads. Reaction pressure rollers or safety claws shall beprovided as required for absorbing negative wheel loads.The buffer stops shall be dimensioned for absorbing atleast the actual buffer end force Sp.2.3.2 Test loads2.3.2.1 General function testThe functions of load pick-up, lifting, lowering, andtravelling of SIR machines are tested by applying thefollowing load:'test load: P k = 1.25 payloadFor the analysis of stresses (overstraining beyond theelastic limit) and of stability the test load P k shall bemultiplied by the reduced lifted load coefficient!...±..Jk.',I,' ='I' 2', The assumed load makes it necessary to proceed asfollows for applying the test load:With the test load applied, all motions shall be individuallytested with reasonable care and with the'load in theleast favourable positions. A motion may not beinitiated before the oscillations caused by the previousmotion' have died down.2.3.3 Emergency catch loads2.3.3.1 Function teSt of the catching deviceOn SiR machines equipped with a speed controlledcatching device, the function test of this device iscarried out by applying the catch load P k = 1.25 . payload.'The catch load shall, be positioned centrally on the loadpick-up device.'The following tests shall be carried out:1) function test of the overspeed governor by loweringthe lifting carriage at excessive speed or by asimulation of this condition;2) 'function test of the catching device by manuallocking of the overspeed,governor during the loweringmotion;3) free-fall stop test of the lifting carriage lifted uptogethe~ with the catch load.The free-fall stop' test according to 3) above can beomitted if the catching device is built up of functiontestedcomponents for which an official certificate hasbeen issued.For the stress analyses according to section 1.2 A "Overstrainingof materials beyond the elastic limit"and B;,Overstrainingof structures beyond the critical bucklingstresses" the catch load shall be multiplied by the increasedlifted load coefficient t/J ".For specifying the increased lifted load values I/J" it hasbeen taken into account that the actual speed for trippingthe catching device v ab considerably exceeds the nominallifting speed VH' which is espressed by the followingequation:: .Vab= -J v g 2 + 2xgxSR + 2xgxSFwhere:Vg preset trip,ping speed of the overspeed governor~ 1.4 x VHSRspacing of the notches of the overspeed governoorin relation to the vertical path of the lifting carriageSF idle path of the catching mechanism until brakingstartsg 9.81 m/s 2The energy equation indicates the mean decelerationduring the catching operation:where:m XV~b22 + m x g x h --'- m x am x h = 0hence:am mean deceleration Ih catching or braking path of the lifting carriagem mass of the test load and of the lifting carriagedead ' weightThe maximum deceleration amax in the event ofcatching results from the characteristic curve of the'working diagram for the catching device and by takinginto account an oscillation coefficient according totable 4.Table 5.2 x am triangular diagramamax ' 1.75 x am trapezoidal diagrljm1.5 x am rectangular diagramThe increased lifted load coefficient I/J" results from therelationship between the maximum deceleration due tobraking and acceleration due to gravity.I/J" =a;axIf an exact calculation of the increased lifted loadcoefficient is omitted, the calculation may be simplifiedby taking I/J" from table 6.Table 6.Approximate figures for I/J"Increased Iifted loadcoefficient I/J" 4)Lifting speed VH (m/min)for catcning approx. work- ~20 ~31.5 ~50 >50by ingdiagram 'Clampingrollercatchingtriangular 5 6 - -deviceBrake typecatching trapezoidal 2.5 3 3.5 -deviceCushioningcatching rectangular 2, 2 2 2device41 The above values for I/J" can be influenced by varying thedesign of the catching device (angle of the sloping surfacein the catching block, width and diameter of the catchingroller)Depending on particular applications, additional calcula;tlons regarding oscillation dynamics may be advisable if dueto its flexibility the structure is definitely capable of absorbinga certain part of the energy produced by catching.
Page 1 and 2: Rules for the Design of Storage and
Page 3: Since the stresses to which the str

FEM 9.311

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