Problem with PSPICE simulation
The issue you are facing, is that, your oscillator has a stable DC operating point. 

Imagine you open-circuit the capacitors. You now have a zero volt input with 100 kOhm source resistance being amplified by U1, which regardless of gain is a 0 V output.

A real oscillator circuit relies on the noise voltage/current generated in circuit to initiate the oscillator.

In a spice simulation you can try: 


Skipping the DC operating point solution
Injecting a small transient current pulse just after t=0
Force a non-steady-state value to one of the circuit nodes in the oscillator loop