KISSsys Template for a Load Spectrum

Transcription

1 KISSsys Template for a Load Spectrum KISSsoft AG Rosengartenstrasse Bubikon Switzerland Tel: Fax: info@kisssoft.ag

2 General Information KISSsys allows user to build a complete gear box or drive train in a single file. Calculations can be then performed easily for the whole system using KISSsoft modules. In case of several load cases (load spectrum or duty cycle) KISSsys can be used to make an analysis of a complete system using this load spectrum. This can be done with the help of a special table or template called 301-LoadSpectrum. Using this template user is able to define load cases for the system and to perform the calculation for all the components with the user defined load spectrum. The lifetime calculations with spectrum are available for the same components as in KISSsoft level. The safety factors and lifetimes of different gears and bearings can be calculated using the spectrum. Additionally shaft fatigue safeties can be calculated using spectrum (DIN743). The rest of the components (where the calculation with spectrum is not possible) are considered to only as check of a weakest component. The load spectrum template functionality allows following types of calculations: 1) Calculation of a gearbox or a transmission with a single load level taken from the load spectrum. 2) Calculation of a gearbox or a transmission with a load spectrum results only with a complete spectrum. 3) Calculation of a gearbox or a transmission with a load spectrum including intermediate results of each load step and results with a complete spectrum. 4) Calculation of a gearbox or a transmission with user defined load (current load) This document describes how to implement and to use the functionality. There is a possibility to extend the spectrum with additional values or setups, this document will also describe where and how user is able to do this (requires administrator to be activated) / 22

3 Contents 1 What can be calculated The following can be calculated Available calculations How to calculate Requirements KISSsoft and KISSsys modules Flow chart Import load spectrum functionality Open templates Copy function to tree structure Functionality General Functions Setup Calculation Setup General Define DefinitionDialog Manual definition Read from file Spectrum type as percentages Spectrum type as absolute values Attaching the load spectrum information to a load input and/or output Additional data in spectrum CreateSpectrum ExportSpectrum Calculations Calculate CalculationDialog Single load level from spectrum Load Spectrum (fast) Load Spectrum with details (slow) Current load settings KISSsoft results External files with spectrum Lifetimes and safety factors according to the calculation Damages with Spectrum calculation Special remark Variables with results Bearing results Gear results Shaft results Functions inside the calculations Calculation functions inside template / 22

4 9.2 Formulas used in lifetime and damage calculation Lifetime Damage Modifying the functionality Gear consideration Additional data Debug / 22

5 1 What can be calculated 1.1 The following can be calculated Table 1 Available calculations Element Safety factors Lifetime Spur-, Helical-, Planetary- and SF, SH, SSint, SB LF and LH per each gear Crossed helical gears Bevel gears SF, SH, SSint LF and LH per each gear Bearings fs (static safety factor) Lh (according to selected method) Shafts SD (fatigue) and SS (static) in the - defined cross sections Other components Weakest component per pin Weakest component per pin 1.2 Available calculations Calculations can be performed with selected load level (single level) according to the spectrum (fast, no details of the pin values) complete calculation results with spectrum and values per each pin 1.3 How to calculate Calculations are performed using KISSsoft and KISSsys functionalities. All the results according to the spectrum (final results) are calculated using KISSsoft spectrum functionalities (except for bearing modules). The results per pin are calculated as well using the KISSsoft calculations with normal settings (single load) and are saved in arrays for latter use. After the calculations the results are written in text- or other types of files and exported from the program. The arrays with detailed results are deleted after the export as a default, but can be saved if debug flag is set on manually (user definition under the functionalities see chapter 10.3). 2 Requirements 2.1 KISSsoft and KISSsys modules To perform the calculations the following KISSsoft modules are required additionally to at least one strength calculation method for the elements which are needed to be calculated. Gear lifetime and safety factors with load spectrum: ZZ1 (Load spectra) including modules Z16, Z16a, Z18, Z18a Shaft calculation with load spectrum WA8 (Load spectra) including modules W01s, W06s KISSsys full version for template implementation and setup SYS module K11c / 22

6 3 Flow chart Yellow fields are only for single load case. Gray fields are only for load spectrum case Load Spectrum table Definition Manual Read from file Calculations Single level load With spectrum Case number Set load step Kinematics yes Details KISSsoft Save no Nof Steps Create element files Messages KISSsoft Nof Steps END Save / 22

7 4 Import load spectrum functionality 4.1 Open templates The template for the load spectrum calculation is not included in the default templates. It can be downloaded from ( and saved for the latter use. User receives a file 301-LoadSpectrum.ks. This file can be copied e.g. into the installation directory of KISSsoft as shown below. Figure 1. Add the templates to the installation directory of KISSsoft An existing KISSsys model can be then opened or a new model can be created for the load spectrum calculation to be added. The administrator mode needs to be activated using Extras/Administrator as shown below to be able to add new functionalities. Figure 2. Open a model and change to administrator mode / 22

8 Then the template can be loaded using File/Open templates and choosing the template file 301- LoadSpectrum.ks. The template will be imported as shown below. The template contains only one table element LoadSpectrum, which includes all the functionalities. Figure 3. Importing templates "301-LoadSpectrum.ks" 4.2 Copy function to tree structure Now that the table LoadSpectrum of the template 301-LoadSpectrum.ks is available, copy and paste the table LoadSpectrum from the Templates to the Model. It is possible to change the name of the table in this process. Figure 4. Copy and paste the table "LoadSpectrum" from the "Templates" to the "Model" After this at least function DefinitionDialog needs to be run once, before switching off the administrator mode again (See more details in chapter 6.2) / 22

9 5 Functionality 5.1 General User needs to define at least three things for the load spectrum (Frequency/Hours, Torque and Speed). Input values can be given to the desired ksysspeedorforce point (a power input or a power output) and values can be entered as absolute values or as fractions of nominal load. Note that values can be only given for those ksysspeedorforce points where these values are constrained. User may select if frequencies (fractions of one) or hours are defined in the spectrum. In case if frequencies are defined also total required lifetime needs to be set. If hours are to be defined, total operational (required) lifetime and frequencies per step are calculated automatically. In case if there is also a gear selection (e.g. vehicle gear boxes) to be considered user may define this in the DefinitionDialog. Additionally to this extra values can be considered in the spectrum. See last chapter of how to do the required setting in this case. 5.2 Functions LoadSpectrum table includes several functions to operate. Some of the functions are for definition, some to perform calculations and some to write results. Order to operate functions in normally as following: Setup 1. DefinitionDialog 2. CreateSpectrum 3. ExportSpectrum Calculation 1. CalculationDialog 2. SaveLoadValues (initialization) (hidden) 3. SaveResultValues (initialization) (hidden) 4. SetLoad (hidden) 5. SaveLoadValues (load spectrum loop) 6. SaveResultValues (if needed in load spectrum loop) 7. CalculateWithSpectrum (hidden) 8. WriteResults (hidden) Hidden functions are automatically operated during the calculation and it is not recommended to use these manually. (Note: if you are still in administrator mode, you will see additional functions (hidden), we therefore recommend to switch of the administrator mode after the definition of the spectrum) / 22

10 6 Setup 6.1 General The following functions are available to do the setup of the spectrum (their use is described in the sections below): Table 2 Functions for load spectrum setup Name DefinitionDialog CreateSpectrum ExportSpectrum Purpose This function will define types and style of data used in the spectrum. It is recommended not to use this function after the first definition if you do not want to change something. When this function is used and OK pressed data in spectrum table is initialized if you have administrator mode activated!!! This function can be used in any time to read in spectrum data from a file The load spectrum information can be written in a *.csv file including the header. 6.2 Define DefinitionDialog First point is to create a load spectrum. That can be done through definition dialog which is called DefinitionDialog. Executing the function a dialog will appear to do the setup for the data. Figure 5. Load spectrum definition dialog / 22

11 Table 3 Load spectrum definition dialog, fields Field Definition: No. of Steps: Spectrum type (speed and torque): Duration type: Required lifetime [h]: Speed defined to: Torque defined to: Consider gears shifts: No. of additional columns Purpose Define load spectrum manually or import from a *csv - file. In case of manual definition number of load steps to be given. (Inactive if import from a file selected) Select definition of Torque and Speed as absolute values or percentages/fractions of user defined nominal load. (Note! If you want to define spectrum as absolute values take care of signs for speed and torque / direction of rotation and Input or Output) Select if Frequency (percentages/fractions of one) or absolute operation hours are to be defined Total required lifetime (operational time) needs to be given if duration type Frequency is selected Select from list SpeedOrForce point where you want to define speed for spectrum. (Only speed constrained points can be selected) Select from list SpeedOrForce point where you want to define torque for spectrum. (Only torque constrained points can be selected) Select if there are gear / power flow shifts in the model Set numbers of how many additional data are defined in the spectrum Manual definition If Manual definition is chosen for field Definition: and No. of Steps: is defined, you will see empty load spectrum table with given number of load steps. User must then manually type in values for all steps. Figure 6. Left: Undefined load spectrum. Right: Defined load spectrum Note! Values for frequency must add up to In case of percentage input selected torque and speed definition must be fraction of nominal values and if inputs as absolute values selected define real values for torque and speed with correct signs Read from file If read from file is selected for field Definition: user must pick up ready made file (*.csv). The file dialog is not automatically shown and needs to be manually opened by executing the function CreateSpectrum - from the table / 22

12 Figure 7. Text file with load spectrum must be selected A text file with a load spectrum must have the following structure: Semicolon (;) as a separator of the fields, at least three values per line in order of frequency/hours;torque;speed. After that the file should contain gear name definition if needed and then all the additional values. See example shown below. This file can be directly generated from the Excel when saving format is selected to *.csv. Note order of the data in the file must be the same as seen in the table header after the definition. Figure 8. Example of spectrum definition as a text file (*.csv) Spectrum is automatically created according to the selected file and will appear to main window as seen in Fehler! Verweisquelle konnte nicht gefunden werden. Right. This file should not contain any other information e.g. no headers of the columns. It is always possible to read in a file later even if manual definition is selected at the beginning. The length of the spectrum can also vary in different files and is not needed to ne adjusted from the DefinitionDialog manually Spectrum type as percentages If spectrum should be defined as percentages, user must enter values in table (or in file to be imported) as fractions of nominal load. (e.g. 0.5 means that calculation is made with 0.5*nominal value or 1.2 means that calculation is made with 1.2*nominal value.) Spectrum type as absolute values In case of definition with absolute values user must enter values in table (or in file to be imported) as real values without unit (e.g. 100 (Nm), 1000 (rpm)). It is very important to take care of signs of values in this case, because sign of the speed defines direction of rotation. Message box of reminder of that will also appear / 22

13 Figure 9. Remember signs of load spectrum values Attaching the load spectrum information to a load input and/or output Use the fields Speed defined to: and Torque defined to: to define at which ksysspeedorforce element the speed and torque information as given in the load spectrum will be used Additional data in spectrum Normally, the calculation of the load spectrum can be run when frequency, torque and speed are defined. There may anyway be cases where the model needs some extra definition (e.g. another input speed or activation of extra connection). In this case user can add additional columns to the spectrum to add these conditions. The additional variable names can be defined using the dialog appearing. Only the valid variable names are accepted. After the definition the variable names will appear in the table definition. Note: Afterwards the setup for the values must be done in the function SetLoad! 6.3 CreateSpectrum This function can be used to read in spectrum data from a ready made file (*.csv). The file dialog is not automatically shown even if read from file is selected in DefinitionDialog and needs to be manually opened by executing the function CreateSpectrum - from the table. Note! Be careful that data is defined similarly in the file as in the definition dialog. If all the information is not available in the file fields are left empty. For more info see chapter 6.2. It is always possible to read in a file later even if manual definition is selected at the beginning. The length of the spectrum can also vary in different files and is not needed to ne adjusted from the DefinitionDialog manually. 6.4 ExportSpectrum The load spectrum information can be written in a *.csv file including the header. If this file needs to be read back to the spectrum user have to modify it so that the header values are removed, otherwise values are not set correctly to the spectrum. 7 Calculations 7.1 Calculate CalculationDialog Once the spectrum has been set up as shown above, calculations can be executed using function CalculationDialog under LoadSpectrum from tree structure. The following dialog will appear to be able to select different calculation types: Figure 10. Calculation type selection dialog Table 4 Calculation types that can be selected in using "CalculationDialog" List position Purpose Single load level from spectrum User may select one load step out of the spectrum and calculate with that value. (Note! After this calculation new nominal load values are according / 22

14 Load Spectrum (fast) Load Spectrum with details (slow) Current load settings to selected line) load case number needs to be set in the filed below the selection Calculates model with given spectrum. Only results with complete spectrum are shown. Calculation is relatively fast, because only kinematic calculations are performed per each step. The KISSsoft results are saved at the end. Calculates model with given spectrum. After every step KISSsoft calculations are called and intermediate values are saved. Calculation is slow, because all KISSsoft calculations are performed per each step Calculation with single load that user has defined for model. This does not really use load spectrum for calculation, but can be used instead of separate calculation function for single load stage. Calculation procedure is also ready made and stores results to the same variables as with load spectrum calculation Single load level from spectrum With this calculation user should select one line/step from load spectrum model to be calculated as a single load. In this case nominal speed and torque are set according to the selected load step, means that current values in selected spectrum definition points are considered as nominal or reference values. Figure 11. Notifications of possible change of nominal load values Load Spectrum (fast) With this calculation method results are calculated using the complete spectrum. Load according to the each load step is set on and after that kinematic calculation is performed. Load values of the components are saved. At the end load spectrums for every calculation are created and KISSsoft calculations are performed using these spectra Load Spectrum with details (slow) This calculation method performs a damage accumulation using Miner rule over the load spectrum. Safety factors for gears are calculated according to spectrum as well as lifetimes for gears and bearings. Single lifetimes of every step are also saved for later use. Damage values for each load step in the load spectrum are also calculated. After calculation user defined nominal load is set back to model. Before the calculation user should take care of application factors for gears (KA). These should be set to 1, but also different values are possible depending on place of the gears in the power train Current load settings The program calculates the model with nominal load which user has defined for model. The results for lifetimes and safety factors are available. It is recommend to use this calculation method instead of KISSsys default calculation method, to ensure that results will be presented in same variables as with other calculation methods and are automatically written out / 22

15 7.1.5 KISSsoft results After using any of above described calculations results are saved in default KISSsys values. E.g. gear safety factors SF1 and SH1 are according to the spectrum if spectrum calculation was selected. 7.2 External files with spectrum After the calculations external result files are created for more detailed results investigation. These files are located in the project folder. Files are called Results.csv and Results.txt including all the calculation results. Further files Damages.csv and Damages.txt are created to show damages of gears and bearings if Load Spectrum with details (slow) is selected. Figure 12. Information about external files created These results files are example files and users are able to adapt the content and appearance of the file by changing the template function for the files. This anyhow requires some in depth knowledge how to do it Lifetimes and safety factors according to the calculation An external Results.csv file is automatically created if calculation is performed with the load spectrum. In this file, all the safety factors and lifetimes for each step are shown. Also frequency, torque and speed values for every gear stages are shown. This file is located in the project folder. Figure 13. Lifetimes and safety factors as listed Damages with Spectrum calculation External Damage.csv file is automatically created if calculation is performed with the load spectrum in details. In this file, the partial damages for all steps in the load spectrum are listed. This file is located in the project folder / 22

16 Figure 14. Damages.csv with partial damages, opened in Excel 7.3 Special remark In case of centrical load elements is present in the calculation model the load and torque values for this element are behaving linearly between all the directions. This is due to the fact that load values Fx, Fz, Fy, Mx, Mz cannot be varied during the spectrum calculation individually and can therefore cause some problems especially if they are expressed with formulas in KISSsys / 22

17 8 Variables with results 8.1 Bearing results The bearing lifetimes with nominal load are saved to the variables (Lh1, Lh2, Lh3 and Lh4). Following new results are available with the load spectrum. The same variables are also available under each bearing element and results are saved in the same manner as under calculation module, but including the values for a single bearing only. Table 5 Variables for bearing results Variable Type Description Lifetime Array Total lifetime according to spectrum of bearings. Lifetime[0] (1 st element) shows the frequency of calculation and should be always one after the calculations. Lifetime[1] (2 nd element) is the lifetime for bearing1, Lifetime[2] (3 rd element) is the lifetime for bearing2 and so on. lifetimes Array Single lifetimes of every load spectrum step. Each array element include lifetimes of all the bearings in the calculation safeties Array Single static safeties of every load spectrum step. Each array element include safeties of all the bearings in the calculation Forces Array Includes the bearisng forces Fr (Fx, Fz) and Fa (Fy) of the every step. 8.2 Gear results The gear safeties with nominal load are saved to variables (SF1, SF2, SH1, SH2 ) and lifetimes to the variable lifetime. Following new results are available with the load spectrum. Table 6 Variables for gear calculation results Variable Type Description Lifetime Array Total lifetime according to spectrum of all gears. Lifetime[0] (1 st element) shows the frequency of calculation and should be always one after the calculations. Lifetime[1] (2 nd element) is the lifetime for root of the gear1, Lifetime[2] (3 rd element) is the lifetime for flank of the gear1, Lifetime[3] (4 th element) is the lifetime for root of the gear2 and so on. lifetimes Array Single lifetimes of every load spectrum step. Every element in array has all lifetimes for whole gear pair (roots and flanks) in same order as in variable Lifetime excluding the first index. safeties Array Single safety factors of every load spectrum step. Every element in array has all safety factors for whole gear pair (roots and flanks) in same order as in variable Lifetime excluding the first index. 8.3 Shaft results Safeties of the defined cross sections are saved under variables SDX, SSX, RDX and RSX / 22

18 Table 7 Variables for shaft results Variable Type Description RXY Real (default variable) Result safety X [%] (S/Smin) at cross-section Y. X=D: fatigue, X=S: at yield point, Y from A-J SXY Real (default variable) Safety X [%] (S) at cross-section Y. X=D: fatigue, X=S: at yield point, Y from A-J safeties Array All safety factors fatigue and static for cross sections over the load spectrum See further chapter 10.3 Debug for information how to save these values / 22

19 9 Functions inside the calculations 9.1 Calculation functions inside template Load spectrum calculation includes a lot of hidden functions, which are used to calculate everything while calculations are executed. Following table explains briefly what all this functions are for. Table 8 Functions in LoadSpectrum Function DefinitionDialog CreateSpectrum ExportSpectrum CalculationDialog SaveLoadValues SaveResultValues SetLoad GearSingleLife CalculateWithSpectrum WriteResults WritekSoftReport Explanation Dialog for defining load spectrum to select necessary inputs for spectrum. This function creates values for the spectrum. In case of manual definition values are set to zero. If this function is called separately user can read values from a file and spectrum is filled according to the data from the file User can write spectrum table to an external *.csv file Dialog to select calculation method. According to selection further functions will be executed. If this function is called with parameter -1 it will initialize new variables Loads for the elements to save load values per each load step. In spectrum calculation this function will save component load values after each step If this function is called with parameter -1 it will initialize new variables safeties and lifetimes for the elements to save intermediate results values per each load step. In spectrum calculation this function will save component results values after each step This function will set correct loads according to the selection or per each load step. If gear selections are activated or there are additional columns in the spectrum, the settings for the data handling must be done here Operated for every load spectrum step to calculate single lifetime for gear with load conditions according to current step. Results save for later use. Called from function LifeWithSpectra Calculates lifetimes, safeties and other values according to the spectrum Writes results according to the calculations in external files Results and Damages These files are saved in the project folder. This function will automatically create whole KISSsoft documentation after each calculation 9.2 Formulas used in lifetime and damage calculation Following formulas are used to do the lifetime and damage calculation for the gears and bearings. Palmgren Miner - rule is used in the calculations / 22

20 9.2.1 Lifetime The total lifetime of a component is calculated from the summarized method from the single lifetimes and time fractions on each bin Damage L htot i 1 i L The total damage of a component is calculated against the total lifetime of the component and required lifetime compared to the bin lifetimes. When the total damage of the each component equals to 100% over the whole spectrum then failure is expected. Against component lifetime D hi i L (9-1) htot i tot D i 1 Lhi D (9-2) i Against required lifetime D i i L hreq tot D i Lhi i D (9-3) / 22

21 10 Modifying the functionality 10.1 Gear consideration If the load spectrum includes the gear selections, a function to do this can (or needs) to be added in the SetLoad function in the table. In case if functionality is not defined there will be a message to do so. Figure 15. Gear selection functionality needs to be defined here E.g. using other special template called 305-SpeedTable gear definition can be defined as follows: Figure 16. Example of definition using "SpeedTable" User may also call hear some own functionalities to do a gear selection or write new function here to do it Additional data In case of additional data is set use the same function SetLoad to define functionality for the additional values. Because there are basically no limitations for these values functionality needs to be set manually as needed case by case / 22

22 Figure 17. Area in "SetLoad" function to define functionality for additional data 10.3 Debug With the load spectrum calculation user can have some more results compared to single load calculations. Additional to the total safety factors and lifetimes, results for lifetimes and damages of single steps are available. See chapter 7.3 for the names of these variables. As a default all these values are deleted after results are written and exported, but it is possible to change local variable debug inside function CalculationDialog. If the values is set different to zero (e.g. debug = 1;) then variables are not deleted and can be searched after the calculations. Figure 18. Saving the intermediated results with debug value different to zero (0) / 22