In your model, you have a "To Workspace" block logging four signals and writing to a workspace variable "simout". Of course, the workspace variable "simout" is going to be over-written in every for-iteration.
In your script, your also specified a return variable "simout" when calling sim(). This is probably a unintended mistake. Not to mention the name conflict (both are called simout but they are logging different contents). simout=sim() can return values but the contents are dependent on the "Data Import/Export" setting in the model Configuration Parameters. You can't use [out1, out2, out3, out4] = sim(mdl) to expect to return those four signals that you want to log.
I suggest the following and you can take a look at one cell of "Loggings"
mdl = 'PSDfaulty';
x = [0.8:0.01:0.95];
for i = 1:numel(x)
set_param([mdl '/FrontFault'] , 'Value' , num2str(x(i)));