About L.E. Prokofieva-Mikhailovskaya, a founder of the first in the USSR laboratory of photoelasticity

Prokofieva-Mikhailovskaya (née Mikhailovskaya) Lydia Eduardovna was born in 1896 in Irkutsk, in the family of an railway engineer. She studied at the Institute of Railway Engineers and from the third year was transferred to the Petrograd University to Physics and Mathematics faculty. After graduation from the university and postgraduate studies, she became an assistant to the Department of Mechanics of the Leningrad State University, which was headed by a professor, later an academician, G.V. Kolosov (1867-1936). First, Prokofieva-Mikhailovskaya conducted practical exercises in the theory of elasticity and headed a laboratory work on the resistance of materials in the mechanical office, which was located in the courtyard of the main building of the University. A problem came into existence in the determination of stress concentration in structures in the design and operation of machines, in connection with a development of industry in 19th & early 20th centuries. Scientists proposed different methods of solving problems: analytical, numerical and experimental. The method of photoelasticity received recognition as one of the effective experimental methods for solving the problems of elasticity theory in early of 20th century. In 1929 Lydia Eduardovna with the assistance of her husband Prokofiev V.K. (Prof. of the State Optical Institute) had assembled his polarization setup and with method of analysis of the bands performed the first work on the investigation of welded joints on the task of the Scientific Research Institute of Shipbuilding. Later, laboratory personnel created instruments for measuring the optical path difference. In addition, the experimental workshops of the NIIMM (Scientific Research Institute of Mathematics and Mechanics of the Leningrad State University) and a manufacture approved of instruments for different tasks for laboratories of the country. Problems that were of great defense importance were solved on the models in the laboratory. In 1930, the first conference on the optical method was held at Leningrad State University. Conferences were held in 1937 and 1941, before the War, and articles on the study of stresses in models were published. In February 1942, L.E. Prokofieva-Mikhailovskaya died of starvation in the corridor of the main building of University in besieged Leningrad, was buried at Volkov cemetery in a mass grave. After the war, the students of Lydia Eduardovna continued the development of the method for solving various problems in the theory of elasticity and thermoviscoelasticity.