At that time, Indians were beginning to leave India and enroll at American universities to purse graduate studies in scientific or technical fields.
While there, he bonded with structural engineer Fazlur Khan, a fellow alum of the University of Illinois, who Iyengar came to regard as an "inspiration and a good friend.
[2] He went on to serve as the director of Structural Engineering at Skidmore, Owings & Merrill's Chicago office from 1975 to 1992[3] and eventually as partner.
[1] Throughout his career, Iyengar has worked with notable architects such as Bruce Graham, Frank Gehry and Walter Netsch.
[3][2] The iconic X-braced tubular system of the Hancock was one of the first projects to use SOM Chicago's computer programs to verify and supplement hand calculations.
[1] In 1986, Iyengar collaborated again with SOM architect Bruce Graham on the cable-stayed steel roof of the McCormick Exposition Center in Chicago.
To solve this problem three different structural systems were used to support the 10 story tall building over the 78 meter clear span.
[2] Iyengar continued to work on the project after his retirement in 1992, being "heavily involved" in developing the steel trusses to achieve the large column-free spans desired inside the museum.
[3] While working on the Pritzker Pavilion band shell in 2000, Gehry was proud to call Iyengar "one of the best structural engineers.