//Use a loop to to pick a reinforcement size that satisfies design checks

SetUnits("Kips & Inches");
DeleteAll();

//Build the model
var h = 20*12;
var w = 5*12;
var v1 = AddVertex(0, 0);
var v2 = AddVertex(w, 0);
var v3 = AddVertex(w, h);
var v4 = AddVertex(0, h);
var area = AddArea(v1, v2, v3, v4);
var mat = "Concrete (F'c = 4 ksi)";

//Apply a lateral load to the top of the wall
var top = FindSide(w/2, h, 0);
SideForce("D", top, 0, 0, 1.0);

//Fix the bottom of the wall
var bottom = FindSide(w/2, 0, 0);
SupportSide(bottom, true, true, true, true, true, true);

//set the mesh size 
//(mesh refinement not shown for example simplicity, see the RefineMesh example)
Mesh(area, 8, mat, 24.0);

//find the name of the design mesh (there is only one)
await DesignMeshing();
var mesh = DesignMeshes()[0];

//turn off minimum steel limits for now and just consider strength
ModifyDesignMesh(mesh, "Min. Steel Ratio", "None");
ModifyDesignMesh(mesh, "ACI 8.6.1.1 Min Steel", "No");

//set the bar spacing to 12 inches
ModifyDesignMesh(mesh, "Reinforcement (Single Mat)", "Y Spacing", "12");

//loop over several rebar sizes, stopping when design checks pass
var bars = new string[] { "#3", "#4", "#5", "#6", "#7", "#8", "#9", "#10" };
foreach(var bar in bars)
{
    ModifyDesignMesh(mesh, "Reinforcement (Single Mat)", "Y Size", bar);
    await Design();
    var unity = Unity(mesh);
    if(unity <= 1.0) { return $"{bar} bars leads to a unity value of {unity}"; }
}

return "No bar size satisfied the design checks.";