Recent advances in MEMS and focal plane array (FPA) technologies have led to the development of manufacturing microbolometers monolithically on a readout integrated circuit (ROIC). In this work, both numerical and finite element methods were performed to simulate the transient electrical and mechanical responses of resistive microbolometer FPAs made by several TCR (thermal coefficient of resistance) materials including a-Si, VOx and semiconducting YBCO. Numerical simulation shows that the pulsed bias readout mode in resistive microbolometer FPAs causes a non-steady-state of the system during the operation. As a result, NETD decreases with the increasing pulse width. In FPAs, the array size, frame rate, ROIC and mechanical reliability set the up-limit to the pulse width. The transient mechanical response for three microbolometer configurations was investigated using finite element modeling. The biased pulse results in membrane bending along the z-axis for the symmetric extended configuration (Type I), or twisting in three axes for the asymmetric extended configuration (Type II) due to the constraint force from the supporting arms. The square configuration (Type III) exhibits the smallest deformation and minimum shear stress at the sharp geometries. a-Si microbolometer generates higher shear stress than other microbolometers with the same square configuration.