Shaft Calculations

The shaft calculation feature is used to calculate deflection lines, bending moments, torsion moments, and factors of safety for shafts or axles put under static loads. You can also use the shaft calculation to determine the strength of the shaft at selected points on the shaft periphery.

With the shaft calculation feature, you can carry out calculation on any of the following:

  • Full or hollow shafts
  • Rotating axles
  • Stationary axles

Before you can start the calculation, you first must define a sufficient support for the shaft. You can then apply force moments, point loads, line loads, or gear forces to the shaft. The material for the shaft can be selected from the DIN or ANSI standards or specified manually.

When defining loads, you may select the option "Dynamic Loads" in the Shaft Calculation dialog box to specify a minimum and a maximum value for the load and to perform calculation for these two values simultaneously.

Note: When performing the strength calculation (based on DIN 743 or ANSI), the following assumptions are made:

  • When a dynamic type of load is applied to the shaft, the average value of that load is assumed to be null.
  • Performing calculation on a rotating axle or on a shaft is carried out in the same way. No torsion moment is considered in case of an axle.
  • A constant and an oscillating bending moment can be applied to a stationary axle. No torsion moment is considered here. For security reasons, the shaft calculation feature uses the maximum amplitude of the oscillating bending moment and the value of the constant bending moment for the strength calculation.

Procedures
To perform calculation on a shaft

You first assign loads and supports to an existing shaft and then perform calculation on that shaft. You can calculate the resultant moments and deflections induced on the whole shaft, or calculate strengths of the shaft at specific points.

  1. Click Content tab Calculation panel drop-down Shaft Calculation. At the Command prompt, enter AMSHAFTCALC.
  2. At the command prompt, choose Create. Then select the shaft on which you want to perform a shaft calculation, and press ENTER.

    Note: If the selected shaft was created with the Shaft Generator, you are prompted to choose whether the contour of the shaft is to be generated. Enter Yes and specify a point in the drawing to insert the generated contour, then proceed to step 4. If you enter No, proceed with step 3.

  3. Select the shaft centerline.
  4. In the Shaft Calculation dialog box, select the part on which you want to perform the calculation: rotating shaft, rotating axle, or not rotating axle.
  5. In the Shaft Calculation dialog box, specify the direction of rotation for the shaft.
  6. In the Shaft Calculation dialog box, choose a type of support. Then select an appropriate point in the drawing to place the support.
  7. Repeat step 6 to insert additional supports.
  8. In the Shaft Calculation dialog box, choose the type of load. Then select an appropriate point in the drawing to place the load.
  9. Repeat step 7 to insert additional loads.
  10. In the Shaft Calculation dialog box, choose Edit.
  11. In the Material Properties dialog box choose Table to specify the type of material for the shaft. Then choose twice OK.
  12. Choose Moments and Deformations.
  13. In the Select Graph dialog box, make your necessary entries. Then choose OK.
  14. In the drawing, specify a point to insert the result of calculation.
Calculate shaft strengths at specific points
  1. Perform steps 1 through 10, as described above.
  2. In the Shaft Calculation dialog box, choose Strength.
  3. Specify a point on the shaft, at which you want to calculate the shaft strengths.
  4. In the Notch tab of the Strength Calculation dialog box, make the necessary changes to the shaft geometry, and click OK.
  5. In the drawing, specify a point to insert the result of calculation, and press ENTER.

Note: S1 and S2 are the calculated safety factor for the fatigue failure and the yielding point, respectively.

To change shaft calculation properties
  1. At the Command prompt, enter AMOPTIONS.
  2. In the Options dialog box, select the AM:Calculation tab.
  3. In the Shaft Calculator section of the AM:Calculation tab, make the necessary entries, and choose OK.
Commands
AMSHAFTCALC

Calculate deflection lines, bending moments, torsion moments, and factors of safety for shafts and axles put under static loads.

 Ribbon: Content tab Calculation panel drop-down Shaft Calculation. Not available on the ribbon in the current workspace.
 Toolbar: Content Calculation
 Menu: Content Calculations Shaft CalculationDoes not exist in the menu in the current workspace.
 Command entry: amshaftcalc

You can perform the calculation on full or hollow shafts, on shafts with or without notches, and you can determine the strength of the shaft at selected points on the shaft periphery.

COMMAND LINE OPTIONS

A prerequisite for starting the shaft calculation is an already drawn shaft.

Select contour or [Create contour/Strength]<Create>: Select a shaft contour in the drawing, enter C to select the objects that make the shaft contour, or enter S to start the Strength Calculation.

Select shaft centerline or [Pick inner point for hollow shaft] <Pick>: Select the shaft centerline.

The command terminates with the error message “non-symmetric shaft” if the selected objects do not build a rotational symmetric shaft.

DIALOG BOX DEFINITIONS

Shaft Calculation dialog box

Use the Shaft Calculation dialog box to assign loads and supports, specify the direction of rotation, select the type of material for the shaft, and to perform calculation on the selected part of the shaft.

Torque dialog box

Use the Torque dialog box to define the torque acting on the shaft.

Point Load dialog box

Use the Point Load dialog box to define the radial point forces acting on the shaft.

Line Load dialog box

Use the Line Load dialog box to define the radial line forces acting on the shaft.

Gear dialog box

Use the Gear dialog box to define the gear load acting on the shaft.

Coupling Gear dialog box

Use the Coupling Gear dialog box to calculate the torque from the power and number of revolution of the coupling gear or from the torsion moment delivered by that coupling gear.

Material dialog box

Use the Material dialog box to select a material for the shaft from the selected standard.

Material Properties dialog box

Use the Material Properties dialog box to change properties of the selected material or to choose a new material altogether.

Configuration dialog box

Use the Configuration dialog box to set configuration for moment and deformation calculation.

Select Graph dialog box

Use the Select Graph dialog box to calculate bending moments, torsion moments, and stresses in the part (shaft, or axle) you selected.

Strength Calculation dialog box

Use the Strength Calculation dialog box to calculate the strength of the shaft at a point that you specify. The calculation is performed according to the DIN or ANSI standard. The factors of safety guarding against fatigue failure and against yield point are also calculated.

DIN Notches dialog box

Use the DIN Notches dialog box to select a DIN type of notch for the strength calculation.

ANSI Notches dialog box

Use the ANSI Notches dialog box to select an ANSI type of notch for the strength calculation.

AM:Shaft tab of the options dialog box

For Segment inserted

 

Overdraw

Overdraws part of the existing shaft when a segment is added to that shaft.

 

Insert

Shifts the whole shaft to one side without overdrawing it, when a segment is added to that shaft.

 

Prompt

Prompts you to choose between the Overdraw and the Insert option.

Stationary Shaft End

 

Left

Keeps the left side of the shaft fixed when a shaft segment is added to or deleted from the shaft.

 

Right

Keeps the right side of the shaft fixed when a shaft segment is added or deleted from the shaft.

NoteWith this option, use only the Edit or Delete option in the Shaft Generator dialog box to edit or delete a shaft segment.
 

Prompt

Prompts you to select the side of the shaft you want to keep fixed.

Adjust Centerline

 

Yes

Adjusts the centerline to the length of the generated shaft.

 

No

Does not adjust the centerline to the length of the generated shaft.

 

Prompt

Prompts you at the end of the shaft generation to decide whether to adjust the centerline to the length of the shaft.

Front View

 

Draw as 2 Halves

Divides the vertical line of the shaft sections at the axis into two lines of the same length.

 

Radius Reflection Line

Draws a reflection line when drawing the radius.

 

Check Contour

Checks whether the contour is broken. A broken contour is highlighted.

Side and Sectional Views

Specifies the way in which side and sectional views of shafts appear and are managed in the drawing.

 

Complete View

Draws both side and sectional view.

 

Radius Reflection Line

Displays the reflection line as a circle in the side view.

 

Sectional with Background

Draws shaft sectional views, including views of objects in the background.

 

Always Update

Updates sectional and side views when you change the shaft. If this option is not selected, you are prompted to decide whether to update the sides and sectional views.

 

Hidden Lines

Shows hidden lines in sectional and side views.

 

Move Side View

Selects a new insertion point for the side view, if the side and front views collide.

View of Interrupt

Specifies how the interrupted view appears: Zigzag, Freehand, or Hatch.

 

Combo box

Displays the selected type of representation for the interrupted view.

NoteA graphical overview of the selected representation appears above this field.
 

Options

Click arrow to list available interruption options.

If shaft is in background, hide standard part, too

 

Yes

Hides a standard part.

 

No

Inserts the standard part in the foreground.

 

Prompt

Prompts you to choose whether to hide a standard part or not.

AM: Calculation tab of the Options dialog box.

Use the AM:Calculations tab to set preferences for fInite element analysis (FEA), bearing calculations, and shaft calculations.

DIALOG BOX DEFINITIONS

FEA

 

FEA - Layer Group for FEA Task

Sets the layer group for the Finite Element Analysis. The default setting is the layer group AM_FEA. You can specify any other layer group to use for the FEA.

 

FEA - Scale Factor for Symbols

Sets the scale factor for symbols associated with the FEA calculation. This factor affects the size in which a symbol appears in the drawing, but not the load value associated with it.

 

Create Output File Automatically

Saves the results of the FEA calculation to a .txt file. The name of the file is the name of the drawing where the FEA routine is being used.

 

Colors

Sets colors for the representation of Isolines and Isoareas. You can select from 12 (VGA graphics driver) or 24 (Super VGA graphics driver) colors. To change preset colors, click the corresponding color field, and select a new color from the color palette.

 

Set Default Colors

Sets colors for the representation of Isolines and Isoareas to the default colors.

Bearing

 

Calculation Mode

Defines the standard for the calculation.

 

Force Unit

Defines the unit of force for the bearing calculation.

 

Length Unit

Defines the length unit to be used for the bearing calculation.

 

Life Adjustment Factor

   

Reliability

Specifies a factor for the reliability of the bearing.

   

Material Factor a2

Specifies a factor for the material.

   

Operator Factor a3

Specifies a factor for operation conditions.

Shaft Calculator

 

Cone Section and Fillet Resolution

   

Default

Automatically determines the number of segments for the ideal representation of the cone section and fillet.

   

Number of Segments to

Determines the number of segments for the representation of the cone section and fillet.

 

Resultant Curve Resolution

   

Default

Automatically determines the number of segments for the representation of the resultant curve.

   

Number of Segments to

Determines the number of segments for the representation of the resultant curve.