Structural Engineering of Arched Truss

Project Info

Case:

We were asked by one of our customers to design an entrance truss for his home. The how was located in a windy and cold region and so the design had to provide a strong truss that could resist all environmental conditions.

Challenges:

In making the design, the engineering team faced the following issues that needed to be considered.

  1. The truss had to withstand the powerful regional wind with the speed as high as 90 mph
  2. The truss had to resist the high snow load during the winter time that was about 40 psf (Pounds per Square Foot)
  3. The design should preserve aesthetics

Solution:

The design team started the work by considering the main requirements for this design. In order to fulfill the first requirement, they considered the mechanical aspects of the entrance truss this provided them with some information about the structure of the truss. They realized that the structure needed to have strong pillars to resists the strong wind power.

Also, in order to consider the 2nd requirement, they made a research on the local soil of the region where the home was located. They considered the frost depth of the soil. Frost depth of a soil or as sometimes called the Frost line refers to the depth to which the groundwater in soil is expected to freeze. This figure highly depends on such parameters as the geographic latitude of the point under consideration, the climatic conditions of the region, the thermal condition of the region’s soil, other heat sources in the nearby location, and etc. Not considering this issue could lead to the collapse of the pillars and bases. To increase the reliability of the design, the design team considered the design for a snow load on the roof equivalent to 50 psf, that is, twice the requested value.

Having considered the above parameters, the design team came up with a design using four triangles in its corner with a classic shape to provide the proper strength of the truss.

The final design was simulated using Solidwork’s Computational Fluid Dynamics (CFD) and Finite Element Method (FEA) analysis tool to make sure about the strength of the structure against a powerful wind at the highest possible speed.

Work done:

In the following link, you can find a report of structural analysis in PDF which has been provided following the client’s demand for designing and calculation for Structural Analysis and Engineering of an Arched Truss of his property.
The design has been also simulated by software and the report of structural analysis simulation follows in the link below:

Report of Structural Analysis 

Description

Results:
The result of wind flow was dragging the structure vertically on one hand, and making a turbulence flow under the structure on the other hand which pushes up the structure and make it unstable.
According to the structural analysis, conclusions, and simulations of this report, the truss can fully bear the proposed situation of wind velocity and snow load, and it thoroughly met the client’s expectations.
Encl.:
1. Solidworks document
2. Solidworks CFD report
3. Solidworks FEA report
4. Cutting List

Client:
Jeff Dardozzi
Date:
October 11, 2017
Location:
US
Category:
Mechanical Engineering