Non linear analysis using optistruct

Hello folks,
I am doing geometric non linear static analysis on a structure and got stuck into some elemental problems

under the material section,
material - matx02

some parameters are given such as

A- plastic yield stress

B - plastic hardening parameter

n - plastic hardening coefficient

C - strain rate coeff.

EPSmax. max possible stress

 

my questions (for titanium ti6al4v)

1. value of A: as per wiki it should be in 90-130 MPa but when I saw some papers value for yield stress was >900MPa

2. B- nothing got from google. what it actually signifies in reality. Please explain.

3. EPSMAX: does its value should be ultimate tensile stress.

 

is there any website available where one can find the values of any material( specially - ti6al4v) in exactly these parameters?

Has anyone got a research article or paper regarding this topic: 'Geometric Non linear compressive analysis of Ti alloy using optistruct'

 

Thanks n regards