REQUEST: Help with LoadCombinations

[JaakkoArokoskiRF]

Hi!

I need help with or example code for how to use Karamba.Loads.LoadCaseCombination or how to add load case combinations to model.

Lets say I have this situation:

        // LoadCases ids
        string loadCaseSnow = "S";
        string loadCaseDead = "D";
        string loadCaseLive = "L";

        // LoadCombinations ids
        string loadCombination1 = "LC1";
        string loadCombination2 = "LC2";
        string loadCombination3 = "LC3";

        // LoadCombination with factors where key is load combination name and value is list of tuples where
        // first item is load case name and second item is factor.
        var combs = new Dictionary<string, List<(string, double)>>();
        combs.Add(loadCombination1, new List<(string, double)>() { (loadCaseSnow, 1.0), (loadCaseDead, 2.0), (loadCaseLive, 3.0)});
        combs.Add(loadCombination2, new List<(string, double)>() { (loadCaseSnow, 4.0), (loadCaseDead, 5.0), (loadCaseLive, 6.0)});
        combs.Add(loadCombination3, new List<(string, double)>() { (loadCaseSnow, 7.0), (loadCaseDead, 8.0), (loadCaseLive, 9.0)});

How I Can do this in Karamba models?

[Clemens-Preisinger]

Hi @JaakkoArokoskiRF,

please find attached examples which show how to specify and evaluate load-case combinations in Karamba3D 3. They will be part of the updated unit-tests-project. I hope this helps.

CantileverLoadCaseCombinationResults_tests.zip ShellLoadCaseCombinationResults_tests.zip WallLoadCaseCombinationResults_tests.zip

[JaakkoArokoskiRF]

Thanks for attachments. I was enabled to construct Karamba.Loads.LoadCaseCombination with this code:

            List<Karamba.Loads.Load> karambaLoads = new List<k3.Loads.Load>();
            if (parameters.AddGravityLoad)
                karambaLoads.Add(GetGravityLoad(analysisModel, parameters));

            karambaLoads.AddRange(distributedForces);
            karambaLoads.AddRange(forcePointLoads);
            karambaLoads.AddRange(forceMomentLoads);
            karambaLoads.AddRange(nodeLoads);

            // Load combinations
            List<Karamba.Loads.LoadCaseCombination> karambaCombinations = new List<LoadCaseCombination>();
            foreach (var myLoadCombination in analysisModel.Loads.LoadCaseCombinations)
            {
                // Code shoudl generate something like this: "LCC = (LC0|LC1|LC2)"
                List<string> rules = new List<string>();
                string rule = $"{myLoadCombination.Value.Name} = (";
                foreach (var loadCase in myLoadCombination.Value.Combinations)
                {
                    // rule += loadCase.Factor + "*" + loadCase.Case.Name + "|";
                    rule += loadCase.Case.Name + "|";
                }
                rule = rule.Substring(0, rule.Length - 1) + ")";
                rules.Add(rule);

                Karamba.Loads.LoadCaseCombination karambaLoadCombination = new LoadCaseCombination(rules);
                karambaLoadCombination.LcName = myLoadCombination.Value.Name;

                if(karambaLoadCombination.IsValid)
                    karambaCombinations.Add(karambaLoadCombination);
            }

            karambaLoads.AddRange(karambaCombinations);

            return karambaLoads;

I am using this method to run analyze:

Karamba.Algorithms.AnalyzeThI.solve(...)

In attachments there seems to be this method which I cannot find where you can give loadcombinations (list of strings) as a list

   Analyze.solve(
                model,
                new List<string>() { "LCC" },
                out IReadOnlyList<double> maxDisp,
                out IReadOnlyList<Vector3> force,
                out IReadOnlyList<double> energy,
                out var outModel,
                out var warningMessage);

            return outModel;

but when I am trying to get reactions with this code its says: "no loadcase found...."

    foreach (string loadcase in loadCases.LoadCombinationsIds)
                    {
                        Karamba.Models.Model model = karambaModel;
                        string lc_id = loadcase;
                        List<int> nodeIndexes = new List<int>() { support.node_ind };
                        List<Plane3> orientations;
                        List<List<Vector3>> forces_all;
                        List<List<Vector3>> moments_all;
                        List<Vector3> sum_forces_all;
                        List<Vector3> sum_moments_all;
                        Karamba.Results.Reaction.solve(
                            model,
                            lc_id,
                            nodeIndexes,
                            out orientations,
                            out forces_all,
                            out moments_all,
                            out sum_forces_all,
                            out sum_moments_all
                            );

                        Vector3 forceVector = forces_all[0][0];
                        Vector3 momentVector = moments_all[0][0];
                        reactions.Add(new SupportReaction(
                            loadcase,
                            forceVector.X,
                            forceVector.Y,
                            forceVector.Z,
                            momentVector.X,
                            momentVector.Y,
                            momentVector.Z
                            ));

                    }

´´´
What I am doing wrong?

[Clemens-Preisinger]

Do you use Karamba3D 3 (see here) or the corresponding nuget package? Use

Karamba.Algorithms.Analyze.solve(
                model,
                lCaseCombiNames,
                out IReadOnlyList<double> lcMaxDisp,
                out IReadOnlyList<Karamba.Geometry.Vector3> lcResultantForce,
                out IReadOnlyList<double> lcElasticEnergy,
                out var outModel,
                out var warning);

to compute the results.