1. Using GSA & Compos for dynamic and footfall analysis 1 Footfall induced vibration analysis using Compos Thomas Li (Software Technology Group)

2. Using GSA & Compos for dynamic and footfall analysis 2Compos  An analysis & design program for simply supported single span composite beams  It can be used to evaluate the footfall induced vibrations of single bay rectangular composite floors  Resotec damping treatment technique is implemented in Compos

3. Using GSA & Compos for dynamic and footfall analysis 3 Footfall induced vibration analysis  It is for single span and single bay composite floors

4. Using GSA & Compos for dynamic and footfall analysis 4 Footfall induced vibration analysis  Mode shapes & frequencies considered uAll frequencies up to 15 Hz uMode shape in composite beam direction – only a half sine curve is considered uMode shape in transverse direction – as many as required

5. Using GSA & Compos for dynamic and footfall analysis 5

6. 6 Footfall induced vibration analysis  Resotec – Artificial damping

7. Using GSA & Compos for dynamic and footfall analysis 7 Footfall induced vibration analysis  Damping material properties uYoung’s modulus uShear modulus uLoss factor Parameter to show the energy loss of a material in vibration Parameter to show the energy loss of a material in vibration It equals the tangent of the phase angle between stress and strain It equals the tangent of the phase angle between stress and strain It equals 2 times the critical damping ratio It equals 2 times the critical damping ratio It should be obtained from the manufacture's specification of the damping material It should be obtained from the manufacture's specification of the damping material

8. Using GSA & Compos for dynamic and footfall analysis 8 Footfall induced vibration analysis – analysis parameters

9. Using GSA & Compos for dynamic and footfall analysis 9 Footfall induced vibration analysis – responses at the centre point

10. Using GSA & Compos for dynamic and footfall analysis 10 Footfall induced vibration analysis – responses along the centre line

11. Using GSA & Compos for dynamic and footfall analysis 11 Dynamic analysis using GSA Thomas Li (Software Technology Group)

12. Using GSA & Compos for dynamic and footfall analysis 12  Modal dynamic analysis  Harmonic analysis  Footfall response analysis  Response spectrum analysis  Time history analysis Dynamic analysis using GSA

13. Using GSA & Compos for dynamic and footfall analysis 13  Modal dynamic analysis uThe uses To estimate structure natural frequencies and mode shapes To estimate structure natural frequencies and mode shapes The basic analysis needed for doing other dynamic response analysis, e.g. harmonic & footfall etc. The basic analysis needed for doing other dynamic response analysis, e.g. harmonic & footfall etc. uAnalysis parameters Number of modes – depend on Number of modes – depend on –Highest frequency requirement, e.g. 15 Hz for footfall analysis –Effective mass ratio, e.g. >90% for seismic response analysis Mass options Mass options –Lumped mass & consistent mass –Mass from applied loads Dynamic analysis using GSA

14. Using GSA & Compos for dynamic and footfall analysis 14  Modal dynamic analysis uMethods available Modal Modal Modal p-delta Modal p-delta Ritz Ritz Ritz p-delta Ritz p-delta uWhat need to know Damping is ignored – if damping is large, e.g. with tuned damper, the results will not be accurate Damping is ignored – if damping is large, e.g. with tuned damper, the results will not be accurate Participation factors – they are for seismic (ground motion) loads only and they are irrelevant to other loading types Participation factors – they are for seismic (ground motion) loads only and they are irrelevant to other loading types Dynamic analysis using GSA

15. Using GSA & Compos for dynamic and footfall analysis 15  Harmonic analysis uThe uses To estimate the dynamic responses of structures under harmonic loads at steady state To estimate the dynamic responses of structures under harmonic loads at steady state To find the peak response and the corresponding harmonic loading frequencies To find the peak response and the corresponding harmonic loading frequencies uAnalysis parameters Spatial distribution and magnitude of the harmonic loads – defined as normal loads Spatial distribution and magnitude of the harmonic loads – defined as normal loads Frequency ranges of the harmonic loads Frequency ranges of the harmonic loads … Dynamic analysis using GSA

16. Using GSA & Compos for dynamic and footfall analysis 16  Harmonic analysis uMain result Harmonic load frequency versus responses from Chart View (displacements, velocities & accelerations) Harmonic load frequency versus responses from Chart View (displacements, velocities & accelerations) Dynamic analysis using GSA

17. Using GSA & Compos for dynamic and footfall analysis 17  Footfall analysis uThe uses To evaluate footfall induced vibrations of floors and stairs To evaluate footfall induced vibrations of floors and stairs uAnalysis parameters Walker’s body weight Walker’s body weight Walking frequency range Walking frequency range Method to be used Method to be used … … Dynamic analysis using GSA

18. Using GSA & Compos for dynamic and footfall analysis 18  Footfall analysis uMethods available Walking on floor – Arup method Walking on floor – Arup method Walking on floor – SCI method (not the latest) Walking on floor – SCI method (not the latest) Walking on stair Walking on stair uWhat need to know The responses are for the footfall loads of a single person walking on floor or stair The responses are for the footfall loads of a single person walking on floor or stair The responses are in vertical direction only The responses are in vertical direction only It is a serviceability limit state check It is a serviceability limit state check Dynamic analysis using GSA

19. Using GSA & Compos for dynamic and footfall analysis 19  Time history analysis To estimate the dynamic responses of structures under applied dynamic loads or ground motions at transient state, e.g. impulse, earthquake and blast loads etc. To estimate the dynamic responses of structures under applied dynamic loads or ground motions at transient state, e.g. impulse, earthquake and blast loads etc.  Response spectrum analysis To evaluate the structure responses under earthquake loads (ground motion) To evaluate the structure responses under earthquake loads (ground motion) Dynamic analysis using GSA