Load Combination & Results Extraction & Documentation

Load combination and analysis results extraction for steel i girder design workflow consists of multiple modular library components. These library objects are;

Unfactored analysis combination (OBPAnalysisCase)

Library Link : https://openbrim.org/objidaziddvhrjxolk0z8zf92xo.libobj?values=LoadType_Input:0%7CisEnvelope:0%7CisIncremental:0%7CisExtreme:0%7CcasesAndFactors:%7C

This library component is a workflow item and is developed for OBP workflow.

The object is created to define unfactored load case combinations/envelopes. With this object, staged construction/deconstruction and other cyclic/static load cases can be combined. The object allows user to filter the case results based on the load type, envelope cases, extract incremental/cumulative results, combine cyclic loads to create most critical load effects.

The name of the core “Combination” object in the library component is added to the name of app instance of the library component in the results spreadsheet. The name of the core combination object is important for result extraction.

Limit States (OBPAASHTOLimitState)

Library Link : https://openbrim.org/objidt1hmdr8fd8oopkivmlna.libobj?values=eta_D:1%7Ceta_R:1%7Ceta_I:1%7CLoadCase1:null%7CMaxLoadFactor1:1%7CMinLoadFactor1:1%7CLoadCase2:null%7CMaxLoadFactor2:1%7CMinLoadFactor2:1%7CLoadCase3:null%7CMaxLoadFactor3:1%7CMinLoadFactor3:1%7CLoadCase4:null%7CMaxLoadFactor4:1%7CMinLoadFactor4:1%7CLoadCase5:null%7CMaxLoadFactor5:1%7CMinLoadFactor5:1%7CLoadCase6:null%7CMaxLoadFactor6:1%7CMinLoadFactor6:1%7CLoadCase7:null%7CMaxLoadFactor7:1%7CMinLoadFactor7:1%7CLoadCase8:null%7CMaxLoadFactor8:1%7CMinLoadFactor8:1%7CLoadCase9:null%7CMaxLoadFactor9:1%7CMinLoadFactor9:1%7CLoadCase10:null%7CMaxLoadFactor10:1%7CMinLoadFactor10:1%7CLoadCase11:null%7CMaxLoadFactor11:1%7CMinLoadFactor11:1%7CLoadCase12:null%7CMaxLoadFactor12:1%7CMinLoadFactor12:1%7CLoadCase13:null%7CMaxLoadFactor13:1%7CMinLoadFactor13:1%7CLoadCase14:null%7CMaxLoadFactor14:1%7CMinLoadFactor14:1%7CLoadCase15:null%7CMaxLoadFactor15:1%7CMinLoadFactor15:1%7CLoadCase16:null%7CMaxLoadFactor16:1%7CMinLoadFactor16:1%7CLoadCase17:null%7CMaxLoadFactor17:1%7CMinLoadFactor17:1%7CLoadCase18:null%7CMaxLoadFactor18:1%7CMinLoadFactor18:1%7CLoadCase19:null%7CMaxLoadFactor19:1%7CMinLoadFactor19:1%7CLoadCase20:null%7CMaxLoadFactor20:1%7CMinLoadFactor20:1%7CLoadCase21:null%7CMaxLoadFactor21:1%7CMinLoadFactor21:1%7CLoadCase22:null%7CMaxLoadFactor22:1%7CMinLoadFactor22:1%7CLoadCase23:null%7CMaxLoadFactor23:1%7CMinLoadFactor23:1%7CLoadCase24:null%7CMaxLoadFactor24:1%7CMinLoadFactor24:1%7CLoadCase25:null%7CMaxLoadFactor25:1%7CMinLoadFactor25:1%7CLoadCase26:null%7CMaxLoadFactor26:1%7CMinLoadFactor26:1%7CLoadCase27:null%7CMaxLoadFactor27:1%7CMinLoadFactor27:1%7CLoadCase28:null%7CMaxLoadFactor28:1%7CMinLoadFactor28:1%7CLoadCase29:null%7CMaxLoadFactor29:1%7CMinLoadFactor29:1%7C

This library component is a workflow item and is developed for OBP workflow.

This object is created to collect the load cases and their max/min load factors accordingly and collects the load modifiers of that limit state. Each instance is a definition of a limit state combination.(Strength/Service/Fatigue/Extreme Event etc.)

This object collects the OBPAnalysisCase as input for 29 different load cases. However, it is not required to set all of these 29 load cases at the same time.

Beware that the name of core combination object "Comb" is originated from OBPAnalysisCase object and is necessary for result extraction. Thus, if the name “Comb” changes, the CaseObjName parameter must be updated accordingly.

The object exports a list of [load case, load type enumeration, modified maximum factor, modified minimum factor, description of load type enumeration] for each load case input. Then, sorts these lists based on their load type enumeration. This sorted list is going to be used for result extraction.

Load Combination Table (OBPAASHTOLimitStateTable)

Library Link : https://openbrim.org/objid75uxbqmoluk9xqssjqiu7m.libobj?values=StrengthI_Input:null%7CStrengthII_Input:null%7CStrengthIII_Input:null%7CStrengthIV_Input:null%7CStrengthV_Input:null%7CExtremeEventI_Input:null%7CExtremeEventII_Input:null%7CServiceI_Input:null%7CServiceII_Input:null%7CServiceIII_Input:null%7CServiceIV_Input:null%7CFatigueI_LL_IM_CE_Input:null%7CFatigueII_LL_IM_CE_Input:null%7C

This library component is a workflow item and is developed for OBP workflow.

This object collects the OBPAASHTOLimitState as input for each limit state combination.

This object is created to collect the previously defined limit states. These limit state inputs are based on AASHTO. Two core combination objects (Max/Min) are created for each limit state input. Overall limit state envelopes are created for each strength-service-fatigue-extreme event limit states. Overall envelope is created using all the combination that are created in the object. The name of each core combination is exported as text for result extraction. Review library object for better understanding.

Results Extraction Object (OBPBase_FECompositeForceExtraction)

Library Link : https://openbrim.org/objidt02vu3q13smozf70dtm5j.libobj?values=DesignComb_Input:null%7CFEComp_Description:0%7CStationList_Input:600,900%7CComputeFor:0%7C

This library component is developed for OBP worfklow but is not a workflow item. The aim of this object is to extract the analysis results of limit states - unfactored load cases - combinations and/or envelopes. The developer must extends this object to input-mapping library objects of code check components.

This object collects OBPAASHTOLimitStateTable , FE description , station list and compute for parameters as input.

The force() functions to be used while extracting the unfactored/factored analysis results & the governing results are guarded based on the ComputeFor parameter. The reason behind this logic is to eliminate the unnecessary result extraction operations and to facilitate parallel processing by keeping the output names symmetrical.

The logic and the list format of the output parameters are illustrated below for 1 limit state combination.

Unfactored Result List

R_XXXCasesPos/R_XXXCasesNeg → This parameter has a complex list of list format. It turns to each unfactored case' negative force and positive force results with their load type enumerations and load type descriptions for 1 limit state combination at each station.

<!-- [station1 results, station2 results,...] -->

<!-- [[case1 results, case2 results,...],[case1 results, case2 results,...],...] -->

<!-- [[[case1 neg],[case1 pos]],[[case2 neg],[case2 pos]],...] -->

<!-- [[[[fx,fy,fz,mx,my,mz],enum,'Enum Desc'],[[fx,fy,fz,mx,my,mz],enum,'Enum Desc'],...],[[[fx,fy,fz,mx,my,mz],enum,'Enum Desc'],[[fx,fy,fz,mx,my,mz],enum,'Enum Desc'],...],...],...] -->

Factored Result List

R_XXXPosMax/R_XXXNegMax/R_XXXPosMin/R_XXXNegMin → This parameter simply turns to factored analysis results at each station for 1 limit state combination. There are 4 variations of factored analysis results of 1 limit state combination. These are;

• Max factor x Max Result

• Max factor x Min Result

• Min factor x Max Result

• Min factor x Min Result

Governing Result List

R_XXXGoverningMax/R_XXXGoverningMin → This parameter simply turns to most critical analysis results (and it’s concurrent forces if applicable) at each station for 1 limit state combination.

There are 2 critical results for enveloped cases. These are; minimum critical results and maximum critical results.

Governing results also turns to overall critical results of each limit state as well as all limit states. Review library object for better understanding.

Load Combination Document Object (OBPDoc_LoadCombination)

Library Link : https://openbrim.org/app/?incubator=1&obj=objidzptu38zopf8086567x9fxod

This library component is developed for OBP worfklow but is not a workflow item. The aim of this object is to tabulate the analysis results systematically and to show transparently which factored result was calculated using which factors and unfactored results.

The Load Combination Document object do not calculate any of the results that are tabulated in the report. All the cases ,enumerations ,factors and results of each limit state combination is an input for the object. And the report tabulates the results only for 1 station or element. If there is a station list or element list, this object must be called in the “Repeat”.

The developer must extends this object to base (2nd layer) object and set the parameters accordingly. (See referencing guide objects ***). Then each DocSection or DocTable of this library component can be referred using “DocRef” in the document of base object.

How to use OBPBase_FECompositeForceExtraction & OBPDoc_LoadCombination

Base object representative : https://openbrim.org/app/?incubator=1&author=Harika_Inanc_&obj=objidjil10cnrlrdhm73dgq7me6

Input-mapping object representative : https://openbrim.org/app/?incubator=1&author=Harika_Inanc_&obj=objid4wjpvtluomdfacm7244sqj

These objects are representing the relationship between OBPBase_FECompositeForceExtraction in map object & OBPDoc_LoadCombination in base object. This example shows how to set critical and concurrent for Fx result parameters for 1 station. The main idea is that force extraction object output results are based on station list but the documentation inputs are based on one station only.