Can Asus a555la be upgraded to hdd+ssd?

Can my laptop be upgraded to ssd + hdd? If yes will that void warranty? Model is A555LA-XX2561T.
Here is specs:
Summary
Operating System
Windows 10 Home Single Language 64-bit
CPU
Intel Core i3 5005U @ 2.00GHz 39 °C
Broadwell-U 14nm Technology
RAM
8.00GB Dual-Channel DDR3 @ 798MHz (11-11-11-28)
Motherboard
ASUSTeK COMPUTER INC. X555LAB (SOCKET 0) 38 °C
Graphics
Generic PnP Monitor (1366x768@60Hz)
Intel HD Graphics 5500 (ASUStek Computer Inc)
Storage
931GB Western Digital WDC WD10JPVX-80JC3T0 (SATA) 36 °C
Optical Drives
HL-DT-ST DVDRAM GUE1N
Audio
Realtek High Definition Audio