0053// Calculation for Virtual Condition and Resultant Condition [1st Year Anniversary <3]
In this post, we will summarize how to calculate virtual condition and resultant condition. Before we go into details how to calculate. We must back to fundamental first -- Definitions.
Definitions:
Virtual Condition -- is constant boundary generated by the collective effects of a considered feature of the size's specified MMC or LMC and the geometric tolerance for that material conditions. (extract from Y14.5-2009: 1.3.67)
Resultant Condition -- is the single worst case boundary generated by the collective effect of a feature of the size's specified MMC or LMC, the geometry tolerance for that material condition, the size tolerance, and the additional geometric tolerance derived from the feature's departure from its specified material condition. (extract from Y14.5-2009: 1.3.51)
Ah ha, basically from the definition itself is hard to visualize if you are newbie in GD&T. So, below will show you six scenarios regarding how to calculate virtual condition and resultant condition.
Scenario 1: Internal Feature + MMC Concept
This on the drawing,
Virtual Condition mean this,
Resultant Condition mean this,
Scenario 2: Internal Feature + LMC Concept
This on the drawing,
Virtual Condition mean this,
Resultant Condition mean this,
Scenario 3: Internal Feature + RFS Concept
This on the drawing,
Inner Boundary mean this,
Outer Boundary mean this,
Note: Based on definition of Virtual Condition and Resultant Condition, Virtual Condition and Resultant Condition only applicable for specification with material condition. Therefore, in Regardless Feature of Size (RFS) Concept, the similar substitutes are inner and outer boundary (please refer to Y14.5-2009: 1.3.2 and Y14.5-2009: 1.3.5 respectively)
Scenario 4: External Feature + MMC Concept
This on the drawing,
Virtual Condition mean this,
Resultant Condition mean this,
Scenario 5: External Feature + LMC Concept
This on the drawing,
Virtual Condition mean this,
Resultant Condition mean this,
Scenario 6: External Feature + RFS Concept
This on the drawing,
Outer Boundary mean this,
Inner Boundary mean this,
Note: Based on definition of Virtual Condition and Resultant Condition, Virtual Condition and Resultant Condition only applicable for specification with material condition. Therefore, in Regardless Feature of Size (RFS) Concept, the similar substitutes are inner and outer boundary (please refer to Y14.5-2009: 1.3.2 and Y14.5-2009: 1.3.5 respectively)
Summary
All in all, these six scenarios can be summarize in two tables below.
Internal Feature (e.g. Hole / Slot):
External Feature (e.g. Shaft / Tab):
*Note: Based on definition of Virtual Condition and Resultant Condition, Virtual Condition and Resultant Condition only applicable for specification with material condition. Therefore, in Regardless Feature of Size (RFS) Concept, the similar substitutes are inner and outer boundary (please refer to Y14.5-2009: 1.3.2 and Y14.5-2009: 1.3.5 respectively
Hope my summary can help you understand virtual condition and resultant condition easily. Cheer!!!
Side Note: 1st Year Anniversary for my CGDTP !!!
This week is the 53th weeks since I receive my ASME Professional Certification, that is great that I can apply my professional knowledge through out my working life. Thanks for those people who give me opportunity to apply and growth my professional. Thanks a lot !!! Love you all !!!
return 0;
