求教abaqus中如何定义两已知属性的材料之间的材料属性？

如图所示，材料1和材料2的属性已知，中间材料的属性从材料1到材料2连续变化（The interfacial region was modeled with the properties continuously varying from region I to region II. Material interlocking was used to obtain the properties of the interface region.）在abaqus中如何定义中间材料属性？
急用，如果能得到各位大神帮助，不胜感激