Hello everyone,
Having a graduate assistantship in engineering schools in USA can be done by one of the following:
1- Coonections: an advisor at your home country knows another one in USA and recommends you to him (very effective way and bypass alot of the admission requirements)
2- Get High GPA (over 3.5) plus high GRE scores
3- emailing professors at schools to get an assistantship offer and this based on the experience and publications mostly