KISSsoft Tutorial: Compression springs acc. EN 13906 1 Starting ...

KISSsoft Tutorial: Compression springs acc. EN 13906
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For Release 102008
kisssoft-tut-014-E-compression-springs.doc
Last modification 31/10/2008 08:36:00
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KISSsoft Tutorial 014: Compression springs
1.1 Starting the software
1 Starting KISSsoft
Start KISSsoft using „Start/Program/KISSsoft 10-2008/KISSsoft“. The following window will
appear:
1.2 Select Calculation
Figure 1.1-1: Start KISSsoft, KISSsoft main window.
Using the Module tree window Tab “Modules”, select the compression springs calculation:
Figure 1.2-1: Selecting compression springs calculation.
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2.1 Task description
2 Analysis of a compression springs
A cold formed compression springs 4 x 32 x 120 (material: spring-steel) should be dimensioned.
Search for:
Spring rate R
Shear stress ô k2 at F 2 =300N
Spring travel s h
Afterwards the input of the following data is explained in this Tutorial:
Wire diameter d
4.0 mm
coil diameter D
40.0 mm
Effective coil n
12.5 mm
Length of relaxes spring L 0
235.0 mm
Material
Draht C (DIN 17223-1), untreated
End of spring
even
Tolerances DIN 2095 quality standard 1
Table 2.1-1: Geometry.
Spring force F 1
150 N
Spring force F 2
300 N
Operating temperature 20.0 °C
Stress
dynamic
Support
fixed/ fixed
2.2 Input of working data
Table 2.1-2: Operating data.
The operating data can be input, as below shown, directly in the input window, as an input of
forces. The input of ways can be given alternatively.
Figure 2.2-1: input window, area: ‚Working data’.
The support kinds are shown in the help picture, which can be open with the „Info Button“ beside
the support. The support coefficient í is used for the calculation of buckling travel s k . If the spring
has not safe for buckling the spring will lead. The spring can buckle without support. If a leading is
required a warning will be shown.
Figure 2.2-2: Warning, the spring buckles and a leading is required.
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2.3 Input Geometry and material
Figure 2.2-1: kind of supports and “support coefficient” í.
KISSsoft offers in his data base a big choice of different compression springs according to
DIN 2098 supplementary sheet 1. The desired spring can be selected from the list directly. In our
example we choose an available spring.
Should the necessary spring not exist, the spring itself can be defined in the list by choice of „own
input“. You find more exact instructions in this tutorial in addition below.
To find a suitable spring in the list, we click before on the Button "Update …". The values
dependent on the input, as for example spring travel, spring forces are thereby calculated etc. and
are indicated. Afterwards an optimum choice can be selected.
By a right mouse click in the select list of the spring you can be determined which values should be
indicated.
Figure 2.3-1: input window, area: ‚Geometry’ - choose of spring.
The type of spring ends, as well as the manufacture and the tolerance will select below the table.
Figure 2.3-2: choose of shown values by right mouse click.
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The material will be selected from a “Dropdown list” or will be defined over own input itself. By
activating the flag in the "check box" for "shot-blasted" in the calculation will be considered that the
wire is shot-blasted.
2.4 Calculation
Figure 2.3-3: choose the material.
If all data are inputted, pressing in the Tool bar the icon “Ó” (or the button F5) in the main window
the analysis will be started (see left marking in Figure 2.4-1) and the results will shown in the lower
section of the main window. Note the status bar shows “Results are consistent” (see right marking
in Figure 2.4-1).
Figure 2.4-1: Starting the analysis and showing consistent results.
In the results window is the appropriate spring rate R shown. In the graphics on the right side below
the results are illustrated. There are a graphics for the force travel diagram and for the dynamic
loads the Goodman- Diagram (if it not available, a diagram will approximate). To enlarge the
graphics can be extracted by the button (right mark ) and scale up.
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Figure 2.4-2: Force-Travel Diagram.
Using in the Tool bar the icon to the right of “”
data, analysis parameters, and results is written.
Name : Unnamed
Changed by : ho on: 16.06.2008 at: 14:44:52
Figure 2.4-3: Goodman Diagram.
(or F6) a report containing all input
Compression springs [F010]
Calculation method: EN 13906-1 (2002)
INPUTS:
Spring geometry
Wire diameter (mm) [d] 4.000
Tolerance analog to DIN 2076 C (mm) [Tol_d] 0.025
Coil diameter (mm) [D] 40.000
Inside diameter (mm) [Di] 36.000
Outside diameter (mm) [De] 44.000
Length of relaxes spring (mm) [L0] 235.000
Effective coils [n] 12.500
Stiff turns [nu] 2.000
Total number of winds [nt] 14.500
Ends of spring
surface flattend
Bearings coefficient 0.500
Material
Material Draht C (DIN 17223-1)
Cold shaped
Not shot peened
Shearing modulus at 20°C (N/mm²) [G20] 81500.000
Tensile strength (N/mm²) [Rm] 1726.000
Shearing Modulus depending on temperature (1/°C) [alphaE] -0.00028
load
Lower spring force (N) [F1] 150.000
Higher spring force (N) [F2] 300.000
Operating temperature (°C) [TB] 20.000
dynamic loading
Results :
Spring rate (N/mm) [R] 3.260
Maximal usable length (mm) [Ln] 77.113
Maximum spring travel (mm) [sn] 157.887
Sum of minimal distance [Sa] 18.750
Force for maximal spring-trave (N) [Fn] 514.713
Block length (mm) [Lc] 58.363 (- 0.362)
Shear stress at block length (N/mm²) [tauc] 916.475
Permissible shear stress at block length (N/mm²) [tauc_zul] 967.000
Stress coefficient [kappa] 1.135
Shear stress [taukh] 270.994
Permissible way stress (N/mm²) [taukh_zul] 321.103
The spring is safe for buckling in the used range
Spring travel for buckling (mm) [sk] 101.548
Spring froce for buckling (N) [Fk] 331.047
Shear modulus at service temperature (°C) [G] 81500.000
Diameter increase (mm) [DeltaD] 0.698
Eigen frequency (Hz) [fe] 72.548
Mass (g) [mass] 181.184
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Load 1
Spring force (N) [F1] 150.000
Spring travel (mm) [s1] 46.012
Spring length (mm) [L1] 188.988
Shear stress (N/mm²) [tau1] 238.732
Adjusted shear stress (N/mm²) [tau1k] 270.994
Load 2
Spring force (N) [F2] 300.000
Spring travel (mm) [s2] 92.025
Spring length (mm) [L2] 142.975
Shear stress (N/mm²) [tau2] 477.465
Adjusted shear stress (N/mm²) [tau2k] 541.987
Utilization of shear stress (static) 0.494
Utilization of shear stress (dynamic) 0.844
Tolerances
According to DIN 2095 quality standard
1
Permissible deviation from
Coil diameter (mm) [AD] 0.300
Lower spring force (N) [AF1] 11.700
Higher spring force (N) [AF1] 13.100
Spring length (mm) [AL0] 3.160
Casing line (mm) [e1] 7.050
Alignment (mm) [e2] 0.660
2.5 Data for own inputs
A special or not available spring will calculate by choosing „own input“ and the data for the spring
will define oneself. Here it is also possible to determine the wire diameter and the effective coils
with help of the spring rate (R = Ä fa / Ä s).
Figure 2.5-1: Own input of spring geometry.
Figure 2.5-2: Sizing of wire diameter.
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