In hot rolling mills, bimetallic rolls consisting of HSS and DCI are extensively used because of their excellent hardness and wear resistance although fatigue failure study is not available. To extend the roll life service, in this study, a three-dimensional finite element method is applied to investigate the rolling stress of the work roll in the four-high rolling mill. To clarify the mechanical stress, zero residual stress is assumed. Then, the fatigue strength is discussed by focusing on several critical points inside of the work roll. The effect of the crown profile at the backup roll surface is clarified as well as the effect of the wear profiles at the work roll surface. It may be concluded that the most critical point is located at the HSS/DCI boundary point B₀²⁷⁰ where (r,z)=(270 mm,0) because the largest stress amplitude appears due to the contact of rolled steel. Another critical point is located at B₇₅₀²⁷⁰ where (r,z)=(270 mm,750 mm) due to the contact of backup roll.

Satellites are utilized in a wide range of fields, such as scientific research, remote sensing, communication, and defense. Unlike ground-based systems, a satellite system has certain special features in terms of system design, usage environment, and life cycle. Therefore, it is difficult for engineers to pass on the system design documents and experiences of the satellite to the next generation. Engineers often design, develop, and validate satellite systems according to their individual competence. In general, if the experience and competence of the engineer are insufficient, regressions and design defects can occur in the later stages of development. In the past, satellites have been affected by problems such as unexpected resource inputs and in-orbit failures, which have reduced quality, cost, and delivery (QCD). We consider that the large gap between the highest standards for satellite design and the actual standards met by the engineers is the most significant factor that causes the QCD to deteriorate. To address this issue, we aim to develop a systems-engineering method that can serve as a guideline for satellite development. Herein, we present the results of our study, along with an evaluation of one of the research themes that we are focusing on to address the aforementioned issue, that is, “Establishing a quantitative systems engineering (SE)-evaluation method by modeling the SE approach.” This is a method for quantitatively visualizing the SE approach and evaluating the validity of satellite development guidelines as a systems-engineering method. This method was validated based on the results of an actual project, i.e., the CanSat project, which involves developing a microsatellite as small as a canned drink.