SAE J1390:2003 pdf download

SAE J1390:2003 pdf download Engine Cooling Fan Structural Analysis
1. Scope—Three levels of fan structural analysis are included in this practice:
1 . Initial Structural Integrity
2. In-vehicle Testing
3. Durability Test Methods
The Initial Structural Integrity section describes analytical and test methods used to predict potential resonance and, therefore, possible fatigue accumulation.
The In-vehicle (or machine) section enumerates the general procedure used to conduct a fan strain gage test. Various considerations that may affect the outcome of strain gage data have been described for the user of this procedure to adapt/discard depending on the particular application. The Durability Test Methods section describes the detailed test procedures that may be used depending on type of fan, equipment availability, and end objective.
Each of the previous levels builds upon information derived from the previous level. Engineering judgment is required as to the applicability of each level to a different vehicle environment or a new fan design. This SAE Recommended Practice is applicable to medium and heavy-duty trucks, buses, construction equipment, industrial, and agricultural equipment. It does not necessarily include passenger cars and light trucks.
1.1 Purpose—The purpose of this document is to identify the general methodology for the structural analysis of engine cooling fans, and to provide expanded information on subset practices within the general methodology, such that a user of this practice can adapt specific subsets related to a vehicle 1 class.
2. References
2.1 Applicable Publications—The following publications form a part of the specification to the extent specified herein. Unless otherwise indicated, the latest revision of SAE publications shall apply.
2.1 .1 SAE P UBLICATIONS —Available from SAE, 400 Commonwealth Drive, Warrendale, PA 1 5096-0001 .
SAE J1 099—Technical Report on Low Cycle Fatigue Properties Ferrous and Non-Ferrous of Materials
SAE J1 1 1 6—Categories of Off-Road Self-Propelled Work Machines
SAE J1 234—Specification Definitions—Off-Road Work Machines
SAE J1 474—Heavy-Duty Nonmetallic Engine Cooling Fans—Material, Manufacturing and Test Considerations
SAE J/ISO 61 65—Earthmoving machines—Basic Types—Vocabulary
3. Initial Structural Integrity
3.1 Scope—It is necessary to identify and attempt to evaluate the characteristics of an application which can have an effect on fan durability. Failures almost always occur in fatigue, so careful attention should be paid to avoid resonance or forced vibration of the fan. This section considers vibrational inputs, fan natural frequencies, and operating speed as part of the initial structural integrity analysis. A fan application fact sheet (Figure 1 ) is recommended as a form to communicate between user and fan supplier.