Provided are assemblies, each including a first structure having a uniform coefficient of thermal expansion (CTE) and a second composite structure having a variable CTE. Also provided are methods of forming such assemblies. The second structure has overlap, transition, and baseline regions. The overlap region directly interfaces the first structure and has a CTE comparable to that of the first structure. The baseline region is away from the first structure and has a different CTE. Each of these CTEs may be uniform in its respective region. The transition region may interconnect the baseline and overlap regions and may have gradual CTE change from one end to the other. The CTE variation with the second composite structure may be achieved by changing fiber angles in at least one ply extending through all three regions. For example, any of the plies may be subjected to fiber steering.