Handling Units in Excel

Use our XLC calculation template to make sure that you never make mistakes with units. One of the most common remarks in the site repository is “I wish this was in metric units” or alternatively “I wish this was in imperial units”. Use our template and simply click from from one system of units to another. The golden rule: ALWAYS use consistent units.

You would think managing units was a trivial exercise but over the years many mistakes have been made through the incorrect use of units. Here are a couple of prominent examples:

In 1983 a Boeing 767 jet ran out of fuel in mid-flight because of two mistakes in figuring the fuel supply of Air Canada's first aircraft to use metric measurements.  Fortunately the crew was able to glide the aircraft safely to an emergency landing at Gimli Industrial Park Airport.

In 1999 NASA lost a $125 million Mars orbiter because one engineering team used metric units while another used US customary units for a calculation. The Mars Climate Orbiter was intended to enter orbit at an altitude of 140.5–150 km above Mars. However, the unit error caused the spacecraft to only reach 57 km. The spacecraft was destroyed by atmospheric stresses and friction at this low altitude.

	Our Video Guide to Handling Units in Excel
	We have decided to produce this video guide to help us handle units sensibly. We’ll show you how to make calculations with interchangeable units simply by the use of the XLC template.

Repository News

The ExcelCalcs repository continues to grow and we are delighted to receive calculations from you. Remember we reward calculations with free XLC Pro subscriptions.
Structural Materials Data Steel
A workbook containing section properties and materials... Thank you InfoJunkie65.
Timber Data for AS1720
Workbook with tables and data relevant fortimber construction. Thank you InfoJunkie65.
Gable Canopy to Australian Codes
Timber canopy design. Thank you InfoJunkie65.

schTechLIB
Technical Libary referenced by most of my workbooks. Thank you InfoJunkie65.

schWindAssessment
Assessment of design wind speed to AS1170.2:2002, and assignment of AS4055 wind classification. Thank you InfoJunkie65.

Kleinlogel
Various frames: rectangular, gable, and skillion, with pinned and fixed bases. Thank you InfoJunkie65.

load combinations.xls

This sheet tabulates loads on connections or other structural components and factors the loads based on strength design and allowable stress design combinations. User can customize load combinations as needed.Thank you jpdgate.

EXCsta2010.xls

Static structural analysis of 2D linear elastic frames and trusses. Computes the static deflections, reactions, internal element forces using direct stiffness methods. Work has started on a 3D version EXCsta_3D.xlsx perhaps you would like to get involved in its development?Thank you Turan Babacan.

WF BEAM AISC360-05 SECTION F2

This is an excel spreadsheet that calculates the allowable moment capacity of a beam with variable unbraced lengths base on section F of the AISC360-05 specification chapter F, section F.2. I am new at this so if anyone can improve upon it, please do so, or let me know what and how i can improve on it. Thank you Margarito Castillo.

2D Frame Analysis
Analysis of a 2D frame subject to distributed loads, point loads and moments. For distributed loads specify length from the ends of the start and end of the load, and the load intensity at the start and end.
For Point loads and moments specify the position and magnitude
Positions and load lengths are measured along the beam axis, as a ratio of the beam length. Distributed and point load direction is either "X" (horizontal) or "Y" (vertical). Thank you Doug Jenkins. 

Plate Bending for Orthotropic Laminates

Laminated plate theory (LPT) or classical lamination theory (CLT) is the basic design tool for evaluating different laminates when experimental data are not available. LPT can be used to combine properties and the orientation of each ply in a predetermined stacking sequence to predict the overall performance characteristics for a laminate. LPT is based on the assumptions that the laminate deforms under conditions of plane stress and that the strains experienced by the individual layers of the laminate are compatible with the strains in the neighbouring layers. The mechanical properties (i.e. the moduli and poisons ratios)of the unidirectional composite are required before LPT can be applied and these are best obtained from mechanical tests. In-plane loading and loading from bending can be considered. LPT can also be used to assess the stresses that arise through temperature and moisture changes. This theory provides the in-plane stresses and strains for each lamina of the laminate and can be combined with failure criteria for individual plies. Thank you rahulmenon.

Orthotropic Plate Buckling and ABD Matrix Calculator

More laminated plate theory (LPT) calculations. Thank you again rahulmenon.

Recommended Reading

Civil engineering text books.

Consultancy Projects - Fatigue Analysis Of Welded structures

Finite element stress analysis.


Understand fatigue classification of welds.


Understand how to select appropriate stress from finite element model for fatigue assessment.


Software developed by MoreVision to take benefit from fatigue enhancement methods (like toe grinding, TIG dressing and stress relieving).


View fatigue classification directly on finite element model.


View damage directly on finite element model.


Export results to spreadsheet for detailed analysis and verification.


Fatigue assessment of rollercoasters.


Fatigue assessment of railway bodyshells and running gear.

Training Modules...

Select  your own course from the ExcelCalcs training modules.

• XLC and ExcelCalcs
  
• Bolting and mechanical fasteners
  
• Welding and joining materials
  
• Static strength and fatigue design
  
• Pins and lugs
  
• Failure criteria and biaxial stress assessment
  
• Material properties and material selection
  
• Steel and aluminium design
• Fatigue of welded structures
  
• Fracture mechanics
  
• Strain gauge or calculate?
  
• Failure Investigations
  
• Design for impact loads and dynamic effects