Keller's *Keller Webinar Series: Liquefaction Mitigation* begins at __27 Oct 2021__

Create a free account and view content that fits your specific interests in structural engineering __Learn More__

Calculation Example Systems Vibration Natural periods # Calculation Example: Natural Periods of Vibration for Systems

Contents [show]

Each of the following columns supports a block of identical mass, m. The columns are fixed at the bottom and free at the top. The height of the first column is twice the height of the second column. The modulus of elasticity, E, and moment of inertia, I, for both columns are the same. The systems have natural periods of vibration of T1 and T2, respectively. Neglecting the weight of the columns, what is the natural period of vibration for the first system?

a. 0.2T_{2}

b. 0.2T_{2}

c. 2T_{2}

d. 3T_{2}

Answer **D**.

SI solution

The stiffness of a cantilever beam is described by

It is known that E_{1}=E_{2} and I_{1}=I_{2}. Since h_{1}=2h_{2}, then:

Since K_{2}=8K_{1} , then:

System 1:

System 2:

Given that m_{1}=m_{2}, it is assumed:

Calculation Example: Axial Force On A ColumnCalculation Example: Shear force On A ColumnCalculation Example: Overturning Moment for Shear panelCalculation Example: Calculate the Change in Length of a Rod loaded in extensionCalculation Example - Calculate the Axial Forces on the Truss MembersCalculation Example - Calculate the member diagramsCalculation Example - Calculate the member diagrams for the beamCalculation Example – Beam with inner hinge (Part A). Find the ReactionsCalculation Example – Beam with inner hinge (Part B). Calculate the member diagrams.Calculation Example – Frame analysis.Calculation Example – Frame analysis – Uniform LoadCalculation Example – Find the Center of Gravity (Surface)Calculation Example – Design bolted connection of tension plates (EC3)Calculation Example – Cantilever BeamCalculation Example – Cantilever Beam, Temperature changeCalculation Example – Undamped free Vibration (Part A).Calculation Example – Undamped free Vibration (Part B).Calculation Example – Evaluation of Structural Property Matrices.Calculation Example – Angular acceleration, angular velocity.Calculation Example – Shear bolt connection EC3.Calculation Example – Buckling of Column (EC3).Calculation Example - Calculate the member diagrams.Calculation Example - Calculate the member diagrams.Calculation Example - Calculate the equation of the elastic curve.Calculation Example - Calculate the location of support.Calculation Example – Plane stress.Calculation Example - Annular cross section, Stress.Calculation Example – Allowable shear force for the girder.Calculation Example - Calculate the deflection. Castigliano Theorem.Calculation Example – Determine the shear force and moment.Calculation Example – Determine the magnitudes of F1,F2.Calculation Example – Internal forces.Calculation Example - Calculate the Axial Forces of the Truss Members.Calculation Example – Calculate the moments of inertia Ix and Iy.Calculation Example – Calculate shear stress for temperature load.Calculation Example – Calculate tension force using virtual work.Calculation Example – Torsional moment-Stress.Calculation Example – Reinforced Concrete Column at Stress.Calculation Example – Cantilever Beam with uniform loading.Calculation Example – Cantilever Beam with point loads.Calculation Example – Rod loadingCalculation Example – Maximum DeflectionCalculation Example – Member Diagram.Calculation Example – Minimum allowable Diameter.Calculation Example – Critical load.Calculation Example – Simple harmonic vibration part1Calculation Example – Simple harmonic vibration part 2Calculation Example – FrictionCalculation Example – Section Modulus SCalculation Example – Plastic Neutral Axis.Calculation Example – Buckling of Column (EC3).Calculation Example – Shear bolt connection EC3.Calculation Example – Member Diagram. Triangular load.Calculation Example – Torsional moment-Stress.Calculation Example – Angular acceleration, angular velocity.Calculate the location of point loadShear bolt connection EC3Torsional Moment-StressCalculate the Axial Forces of the Truss MembersCalculate the Maximum Shear StressHow to calculate yield strengthCalculate angular velocity, angular accelerationTemperature ChangeAverage shear stress in pressure vesselAllowable shear force of the girderCalculation ExamplesCalculate the variation in length of the rodSpring Assemblies in Series/Parallel: Two Springs in SeriesTruss vs CableCalculate the vertical deflection of a beamFlexular Crack in Concrete BeamMaximum Factored Vertical Shear

A simply supported beam (Figure) with a span...

For the simply supported beam of Figure 1, deter...

Calculate the vertical deflection of the beam (m...

Truss and cable elements are defined by their ab...

Based on Figure 1, we get: where:...

The rod of the picture is loaded with the force 2...