Criteria for evaluation of the hardening factor of machine parts

V. Ya. Chubar' Zaporozhe Machine Building Institute. Translated from Problemy Prochnosti, No. 3, pp. 62–65, March, 1989.     

Criteria for the increase in strength of parts subjected to surface-diffusion treatment

An analysis of factors determining the variation in the endurance of steels due to surface hardening by diffusing various elements is presented.     

Reflectometer for measuring the roughness of the treated surfaces of machine parts

A new design of reflectometer is described. Theoretical relations that are presented make it possible to account for the difference in local heat-transfer coefficients and thus reduce the roughness measurement error.Translated from Izmeritel'naya Tekhnika, No. 9, pp. 27–30, September, 1995.     

Measurement of the coordinate dimensions of machine parts

Definitions are formulated for the real values of linear and angular coordinate dimensions of machine parts in accordance with the theory of basing, taking into account their purpose and informativeness of their geometric elements. The informativeness of the coordinate planes and axes of generalized and auxiliary coordinate systems of machine parts with normalization of the coordinate dimensions are demonstrated. A methodology of true measurements of coordinate dimensions is proposed. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 18–22, July, 1998.     

Criteria for the existence of generalized surface spin waves

A criterion for the existence of generalized surface spin waves is proposed on the basis of an analysis of the dipole-exchange surface spin dynamics of a tangentially magnetized, semibounded, easy-axis antiferromagnet. Pis’ma Zh. Tekh. Fiz. 24, 70–75 (July 12, 1998)     

Criteria for evaluating protection from single points of failure for partially expanded fault trees

Fault tree analysis (FTA) is a technique that describes the combinations of events in a system which result in an undesirable outcome. FTA is used as a tool to quantitatively assess a system's probability for an undesirable outcome. Time constraints from concept to production in modern engineering often limit the opportunity for a thorough statistical analysis of a system. Furthermore, when undesirable outcomes are considered such as hazard to human(s), it becomes difficult to identify strict statistical targets for what is acceptable. Consequently, when hazard to human(s) is concerned a common design target is to protect the system from single points of failure (SPOF) which means that no failure mode caused by a single event, concern, or error has a critical consequence on the system. Such a design target is common with “by-wire” systems. FTA can be used to verify if a system is protected from SPOF. In this paper, sufficient criteria for evaluating protection from SPOF for partially expanded fault trees are proposed along with proof. The proposed criteria consider potential interactions between the lowest drawn events of a partial fault tree expansion which otherwise easily leads to an overly optimistic analysis of protection from SPOF. The analysis is limited to fault trees that are coherent and static.