Index: /issm/trunk-jpl/src/m/classes/frictionschoof.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/frictionschoof.m	(revision 23894)
+++ /issm/trunk-jpl/src/m/classes/frictionschoof.m	(revision 23895)
@@ -53,6 +53,4 @@
 			WriteData(fid,prefix,'class','friction','object',self,'fieldname','Cmax','format','DoubleMat','mattype',1,'timeserieslength',md.mesh.numberofvertices+1,'yts',md.constants.yts);
 			WriteData(fid,prefix,'class','friction','object',self,'fieldname','m','format','DoubleMat','mattype',2);
-			
-
 		end % }}}
 	end
Index: /issm/trunk-jpl/src/m/classes/frictiontsai.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/frictiontsai.m	(revision 23895)
+++ /issm/trunk-jpl/src/m/classes/frictiontsai.m	(revision 23895)
@@ -0,0 +1,57 @@
+%FRICTIONTSAI class definition
+%
+%   Usage:
+%      frictiontsai=frictiontsai();
+
+classdef frictiontsai
+	properties (SetAccess=public) 
+		C = NaN;
+		f = NaN;
+		m = NaN;
+	end
+	methods
+		function self = frictiontsai(varargin) % {{{
+			switch nargin
+				case 0
+					self=setdefaultparameters(self);
+				otherwise
+					error('constructor not supported');
+			end
+		end % }}}
+		function self = extrude(self,md) % {{{
+			md.friction.C    = project3d(md,'vector',md.friction.C,'type','node','layer',1);
+			md.friction.f = project3d(md,'vector',md.friction.f,'type','node','layer',1);
+		end % }}}
+		function self = setdefaultparameters(self) % {{{
+
+		end % }}}
+		function md = checkconsistency(self,md,solution,analyses) % {{{
+
+			%Early return
+			if ~ismember('StressbalanceAnalysis',analyses) & ~ismember('ThermalAnalysis',analyses), return; end
+			md = checkfield(md,'fieldname','friction.C','timeseries',1,'NaN',1,'Inf',1,'>',0.);
+			md = checkfield(md,'fieldname','friction.f','timeseries',1,'NaN',1,'Inf',1,'>',0.);
+			md = checkfield(md,'fieldname','friction.m','NaN',1,'Inf',1,'>',0.,'size',[md.mesh.numberofelements,1]);
+		end % }}}
+		function disp(self) % {{{
+			%See Brondex et al. 2017 
+			disp('Tsai sliding law parameters:');
+			disp('   Tsai''s sliding law reads:');
+			disp('     ');
+			disp('      tau_b = -  min(C |ub|^(m-1) , f N) u_b   ');
+			disp('                                                   ');
+			disp(' ');
+			fielddisplay(self,'C','friction coefficient [SI]');
+			fielddisplay(self,'f','Iken''s bound (typically between 0.17 and 0.84) [SI]');
+			fielddisplay(self,'m','m exponent (generally taken as m = 1/n = 1/3)');
+		end % }}}
+		function marshall(self,prefix,md,fid) % {{{
+			yts=md.constants.yts;
+
+			WriteData(fid,prefix,'name','md.friction.law','data',12,'format','Integer');
+			WriteData(fid,prefix,'class','friction','object',self,'fieldname','C','format','DoubleMat','mattype',1,'timeserieslength',md.mesh.numberofvertices+1,'yts',md.constants.yts);
+			WriteData(fid,prefix,'class','friction','object',self,'fieldname','f','format','DoubleMat','mattype',1,'timeserieslength',md.mesh.numberofvertices+1,'yts',md.constants.yts);
+			WriteData(fid,prefix,'class','friction','object',self,'fieldname','m','format','DoubleMat','mattype',2);
+		end % }}}
+	end
+end