private void writeSteelDesignProps(XmlWriter xml, Material.Material mat)
{
MaterialDesignProps dProps = mat.DesignProperties;
if (dProps.GetType().Name.Equals("SteelDesignProps"))
{
SteelDesignProps props = (SteelDesignProps)dProps;
xml.WriteStartElement("Material");
xml.WriteAttributeString("Material", mat.Name);
xml.WriteAttributeString("Fy", props.Fy.ToString());
xml.WriteAttributeString("Fu", props.Fu.ToString());
xml.WriteEndElement();
}
}