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Kemetals

Metal Buildings & Structures
Tower

Tower

Steel Metal Tower But From Bottom View Structural Prospective
Store

Store

Modern Pre-engineered Buildings Made Of Light Built Up Sections & Cold Formed Purlins & Girts
Military Hanager

Hangar

Military Aircraft Hangar Made of built Up Steel Columns And Roof Trusses
UniPoler

UniPole

Support for Cables, Transmission, Sign Boards made from Single Steel Pipe Column
Crane

Crane

Giant outdoor Gantry Heavy Crane
Glazing

Glazing

Mullions to Support Stunning Architectural Glazing System
Kakulta Bride

Bridge

Truss Bracing For Bridge Chord
MultiStory

"MultiStory

Flat Bar Diagonal Bracing For Multistory Steel Building
Revited Bridge

Bridge

Classic Historical Riveted Bridge Over a River
Aircraft Hangar

Hanger

Giant Passangers Aircraft Arched Hangar
Sydney Bridge

Bridge

Walk Way On The Top Truss Chord Of Suspended Bridge

Metal Structures design is the art of selecting the structure optimum sections & connections from materials which their properties are uncertain and assessing developed stresses & displacements using approximate analysis methods under probable combinations of loads that their values can only be predicted so that to have a fully safe serviceable economic structure.

by anonymous author

Sections

Enormous number of different shapes and designations is available for Steel Sections, they are used with different reference specifications that set required dimensions and tolerances for each, Below is illustration of sample of most commonly used Hot Rolled I Shapes used in the metal structures
Cold Formed Sections are also intensively used in Metal Structures, while they are commonly used as secondary framing elements in pre-engineered building and structure steel buildings, however those light sections can be used as main elements in light construction including residential multistory buildings and they are also referred as Light Gage section, below are some common section shapes

Connections

Metal Members Connections may include different arrangements of plates, cleats and stiffeners as per structural design requirements but typically all connections include either bolts or welds or both in the same connection.
Structural Bolts are available with mild and high strength grads, The most recognized International Specifications for structural Bolts are:-
American ASTM A325, A490 and the recent F3125 and many others
European Bolts mechanical properties & Grades are according to EN ISO 898 while specifications for Shape & dimensions includes ISO 4015, ISO 4017, ISO 4018 and many others
Indian Standard main structural bolts specification is IS 1363.
Most specialized standard comprehensive set of Welding codes is the American welding Society AWS, European standards for welding includes EN ISO 15609, EN ISO 15614 and many others, Indian Standards for welding includes IS 817, IS 818 and many others.

Welding

Bolting

Below illustration of Sample Connection for Mezzanine beams to one web side main frame column with upper diagonal members with tube sections and a stitched portal bracing column on the other side.
2D

Connection 2D Illustration

3D Illustrative
Illustrative Solid 3D
3D Annotated
Annotated Solid 3D
The interactive same above detail is in the below 3D Web viewer, Hold left mouse button and move to navigate and explore all connection components.


Take The Control

The design of connections can be the most critical task in the process of designing metal buildings and structures as mostly connections failure modes are brittle unlike ductile failure within the steel members, Applicable Design codes usually gives certain component capacities while the complicated stresses distribution inside the connection itself are either obtained by research driven closed form equations or by solving finite elements computer simulation, sample output for simulation performed by Kemetals of the above connection is in below slide.
Normal Stresses

Normal Stresses

Shear Stresses

Shear Stresses

Bolts Forces

Bolts Forces

Deformations

Deformations

Analysis

Typically all Structures are composed of a large number of members that are connected to each other’s and interacting to one another just same as any living being, all members experiences stress and strains. The structure responds to the external loads by creating load paths through its members, those load paths are depending on size, arrangement, material and type of connections between different members, the mathematical method that Engineers use to calculate straining actions on different members is the Structural Analysis that is based on Theory Of Structures.
The concept of framework analysis emerged during the period from 1850 to 1875, at this time the concepts of matrices were being introduced and defined, These concepts are the foundations of matrix structural analysis, which did not take form until nearly 80 years later to form what is know The Direct Stiffness Method.
The Demomstration of a sample simple beam stiffness matrix is as below
Beam Elastic Line

Beam Elastic Line

The strainging actions of a Simple Beam at both Ends 1 & 2 can be evaluated using the following Matrix Form as a function in the beam elastic line above deformed shape: \begin{align*} \begin{Bmatrix} V_{1}\\ M_{1}\\ V_{2}\\ M_{2} \end{Bmatrix} & = \frac{EI}{L^{3}} \begin{pmatrix} 12 & 6L & -12 & 6L\\ 6L & 4L^{2} & -6L & 2L^{2}\\ -12 & -6L & 12 & -6L\\ 6L & 2L^{2} & -6L & 4L^{2} \end{pmatrix} \begin{Bmatrix} v_{1}\\ \theta _{1}\\ v_{2}\\ \theta _{2} \end{Bmatrix} \end{align*} The above now is in the form $$ \{p\}=[K]\{d\} $$ The Beam stiffness matrix [K] is : \[ \left[ K \right] = \frac{EI}{L^{3}} \begin{pmatrix} 12 & 6L & -12 & 6L\\ 6L & 4L^{2} & -6L & 2L^{2}\\ -12 & -6L & 12 & -6L\\ 6L & 2L^{2} & -6L & 4L^{2} \end{pmatrix} \]