Famous for saying "form ever follows function", michael graves and his ideas were the inspiration for the international style architects who built practical buildings that clearly showed structural supports and banished all ornament.

You're describing Modern architecture, which predominated in the first half of the 20th century, and especially in the years after World War II.

The idea of "form follows function" meant that buildings should be practical, built to be efficient and improve people's lives, and not focus on ornate or decorative features.  Michael Graves' early work as an architect was in the Modern style.

Graves, however, along with other architects such as Frank Gehry, Philip Johnson, Charles Moore, and Robert Venturi, later pursued a style of architecture that was less serious about itself than the Modern architecture trend had been.  Graves and others developed the Postmodern trend in architecture, which features all sorts of odd shapes and striking design features -- with form taking a primary role once again over function.  The Postmodern style began to emerge already in the 1960s and became strongly evident in the 1980s and 1990s.