public void InitializeGeometry(CartesianPoint crackMouth, CartesianPoint crackTip)
{
this.crackMouth = crackMouth;
crackPath.Add(crackMouth);
var segment = new DirectedSegment2D(crackMouth, crackTip);
double tangentX = crackTip.X - crackMouth.X;
double tangentY = crackTip.Y - crackMouth.Y;
double length = Math.Sqrt(tangentX * tangentX + tangentY * tangentY);
double tangentSlope = Math.Atan2(tangentY, tangentX);
this.crackTip = crackTip;
crackPath.Add(crackTip);
tipSystem = new TipCoordinateSystem(crackTip, tangentSlope);
CrackTipEnrichments.TipSystem = tipSystem;
tangentX /= length;
tangentY /= length;
foreach (XNode node in Mesh.Nodes)
{
levelSetsBody[node] = segment.SignedDistanceOf(node);
levelSetsTip[node] = (node.X - crackTip.X) * tangentX + (node.Y - crackTip.Y) * tangentY;
}
if (LevelSetLogger != null)
{
LevelSetLogger.InitialLog(); //TODO: handle this with a NullLogger.
}
}
public void UpdateGeometry(double localGrowthAngle, double growthLength)
{
double globalGrowthAngle = MathUtilities.WrapAngle(localGrowthAngle + tipSystem.RotationAngle);
double dx = growthLength * Math.Cos(globalGrowthAngle);
double dy = growthLength * Math.Sin(globalGrowthAngle);
double unitDx = dx / growthLength;
double unitDy = dy / growthLength;
var oldTip = crackTip;
var newTip = new CartesianPoint(oldTip.X + dx, oldTip.Y + dy);
crackTip = newTip;
tipSystem = new TipCoordinateSystem(newTip, globalGrowthAngle);
var newSegment = new DirectedSegment2D(oldTip, newTip);
foreach (XNode node in Mesh.Nodes)
{
// Rotate the ALL tip level sets towards the new tip and then advance them
double rotatedTipLevelSet = (node.X - crackTip.X) * unitDx + (node.Y - crackTip.Y) * unitDy;
levelSetsTip[node] = rotatedTipLevelSet - newSegment.Length;
if (rotatedTipLevelSet > 0.0) // Only some body level sets are updated (See Stolarska 2001)
{
levelSetsBody[node] = newSegment.SignedDistanceOf(node);
}
}
}
public HashSet <XNode> Update(CartesianPoint oldTip, double localGrowthAngle, double growthLength, double dx, double dy,
IReadOnlyList <XNode> allNodes, ISet <XNode> crackBodyNodesAll,
Dictionary <XNode, double> levelSetsBody, Dictionary <XNode, double> levelSetsTip)
{
double unitDx = dx / growthLength;
double unitDy = dy / growthLength;
var newTip = new CartesianPoint(oldTip.X + dx, oldTip.Y + dy);
var newSegment = new DirectedSegment2D(oldTip, newTip);
var crackBodyNodesModified = new HashSet <XNode>();
foreach (XNode node in allNodes)
{
// Rotate the ALL tip level sets towards the new tip and then advance them
double rotatedTipLevelSet = (node.X - oldTip.X) * unitDx + (node.Y - oldTip.Y) * unitDy;
levelSetsTip[node] = rotatedTipLevelSet - growthLength;
// Only some body level sets are updated (See Stolarska 2001)
// WARNING: this is quite dangerous. If the crack turns/kinks sufficiently over its whole history, then nodes far
// alway from the tip that should remain unchanged, will get different level sets. A new formula is needed to
// avoid messing them up. In a narrow band approach, it may be possible to limit the level set update in nodes
// near to the old tip the new tip or the inbetween segment.
if (rotatedTipLevelSet > 0.0)
{
levelSetsBody[node] = newSegment.SignedDistanceOf(node);
if (crackBodyNodesAll.Contains(node))
{
crackBodyNodesModified.Add(node);
}
}
}
if (crackBodyNodesModified.Count != 0)
{
Console.WriteLine("There are nodes that were previously enriched with Heaviside, but now their level set"
+ " changes. For 1st order LSM, this usually indicates that the crack has turned sufficiently towards"
+ " its original geometry. In that case, the body level set of these nodes is computed from the crack"
+ " extension far away from their position and is thus incorrect. These nodes are: ");
foreach (var node in crackBodyNodesModified)
{
Console.WriteLine(node);
}
Console.WriteLine();
}
return(crackBodyNodesModified);
}
public void InitializeGeometry(CartesianPoint crackMouth, CartesianPoint crackTip)
{
CrackMouth = crackMouth;
var segment = new DirectedSegment2D(crackMouth, crackTip);
double tangentX = crackTip.X - crackMouth.X;
double tangentY = crackTip.Y - crackMouth.Y;
double length = Math.Sqrt(tangentX * tangentX + tangentY * tangentY);
double tangentSlope = Math.Atan2(tangentY, tangentX);
this.crackTip = crackTip;
tipSystem = new TipCoordinateSystem(crackTip, tangentSlope);
tangentX /= length;
tangentY /= length;
foreach (XNode node in Mesh.Nodes)
{
levelSetsBody[node] = segment.SignedDistanceOf(node);
levelSetsTip[node] = (node.X - crackTip.X) * tangentX + (node.Y - crackTip.Y) * tangentY;
}
}