{
  "joints" : [ { "x": 0, "s": true, "F": 0 }
	       { "x": 0.1, "s": false, "F": -40 }
	       { "x": 0.5, "s":false, "F": 10 }
	       { "x": 0.7, "s":true, "F": 0 } ],
  "bartypes" : [ { "E" : 2e-5, "lims": 1e-4, "limc": 1e-4 } ],
  "bars" : [ { "j_0": 1, "j_L" : 2, "A": 0.03, "q" : 0, "type" : 1 },
	     { "j_0": 2, "j_L" : 3, "A": 0.02, "q" : 20, "type" : 1 },
	     { "j_0": 3, "j_L" : 4, "A": 0.04, "q" : -30, "type" : 1} ]
}