I want my piezos to have a center voltage at 2.5V for a 0-5V ADC input on Atmega328, so it can sense force in both ways - one way would be >2.5V and the other will be <2.5V.
Will this circuit work? Or any improvments?
Slight improvement (less power consumption and fewer parts):
U1 has to be very low input bias current, of course. You might want to add some series resistors to the non-inverting inputs in case the piezo voltage exceeds 2.5V.
If the resistors R3 and R4 are 1MΩ( in LTspice; 1m = 1 milli Ω , 1M = 1 mega Ω ) your circuit will work. For some additional improvements, you can take a look at the frequency response of your circuit. To do that you will need to change your model a little bit and consider some additional capacitances. Take a lot here for a very intuitive guide. Hope it helps!