If EN 13445-3 is selected in the Fatigue model/code drop-down menu in Project Setup dialog box in 5.1 Data Entry and Project Setup, the EN 13445-3 button on the toolbar becomes activated. The program follows the procedure in Chapter 18 "Detailed assessment of fatigue life".
Choose Input>EN 13445-3 or click EN 13445-3 button. The EN 13445-3 Input dialog box appears.
5.4.1 Selecting Material
The user can choose EN material or ASME Sec. II Part D material, or manually enter or modify material properties.
If EN material is selected, the EN Material group box is activated.
Select a material database from EN 10216 Seamless tubes, or EN 10217 Welded tubes, or EN 10028 Flat products, or EN 10222 Forgings, or EN 10213 Castings, or EN 10269 Fasteners, or EN 10273 Weldable bars. Then the Steel Name drop-down menu is activated. Select a material from the drop-down menu.
If ASME Sec. II Part D is selected, the ASME Material group box is activated. Select a material from Spec No. dropdown menu.
If Manually enter or modify radio button is clicked, the Manually enter properties dialog box pops up:
Enter material name, tensile strength at ambient temperature, yield strength at ambient temperature, and yield strength at reference temperature. Specify either the steel is feritic or austenitic by check corresponding radio button. Click Ok button to confirm and close the dialog. To come back and make changes, click Edit button to open the dialog box.
5.4.2 Selecting Component
The Component Selection group box contains three options:
oEN 13445 Welded material - Welded details. Influenced by classification of weld details, thickness, either equivalent or principal stress.
oEN 13445 Unwelded component - Unwelded component. Influenced by wall thickness, surface condition and stress concentration factor.
oEN 13445 Bolt - Bolt with given diameter.
5.4.3 EN 13445 Welded material
If EN 13445 welded material is selected, the EN 13445 Welded Material group box is activated.
Choose a fatigue curve by clicking either Equivalent stress fatigue curve radio button or Principal stress fatigue curve radio button.
Enter thickness of stressed member under consideration. The thickness will be used for size effect factor calculation.
Select class of weld detail by clicking Select button, and the following dialog window will display.
Browse the tabs on the top to find out the matching weld detail. Click one of the radio buttons to select the Class according to weld detail and testing group. Click OK button to confirm and return to previous window. The class of weld detail will be displayed in the box. The class of weld detail box is read-only; the content can only be edited by clicking Select button.
Note that the screen shot above shows equivalent stresses based classification of weld details. If principal stress fatigue curve is chosen, the dialog window will show principal stress based classifications.
5.4.4 EN 13445 Unwelded component
If EN 13445 welded material is selected, the EN 13445 Unwelded Component group box is activated.
Enter wall thickness. The thickness will be used for size effect factor calculation.
Click Surface condition drop-down menu, select appropriate surface roughness Rz according to surface finish condition. If Custom Rz value is selected, enter a Rz value in the box.
Enter Stress concentration factor Kt. If Entered stresses are total peak stress checkbox is checked, the stress values are considered peak values and the nominal stresses will be peak values divided by Kt; if unchecked, the stress values are considered nominal values and the peak stresses will be nominal values multiplied by Kt;
5.4.5 Fatigue Curve Type
The Fatigue Curve Type group box contains two options:
oConstant amplitude loading - a cyclic loading in which all the load cycles are identical.
oVariable amplitude loading - a cyclic loading in which the amplitude of loading varies with time or with loading steps.
Select the fatigue curve type that is appropriate.
5.4.6 Plasticity Correction Factor
Select Mechanical origin if the plasticity is due to mechanical stresses; choose Thermal origin if the plasticity is driven by thermal stresses.
The input information box at the bottom of the window displays inputted data. Every time as data changed, the information box will be updated.
Click Plot fatigue curve button. The Fatigue Curve window appears. You can zoom, print or export the chart, or change the styles of the chart by clicking the buttons on the tool bar. Click X button on the upper-right corner to close the window.
When completed, click OK button to return to the main window.