Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 1 Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas FEM Analysis PM# June 2006

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 2 STATUS OF THE FEA MODEL AND ACTIVITIES DONE UP-TO-NOW FEA MODEL - THE FEA MODEL HAS NOT BEEN UPDATED BECAUSE THERE ARE NO BIG CHANGES IN THE DESIGN - WE ARE WORKING IN ORDER TO FREEZE SEVERAL SMALL CHANGES IN THE DESIGN COMING ALSO FROM THE INDUSTRIALISATION REQUIREMENTS - MAIN CHANGES TO BE INTRODUCED: NEW LAYOUT OF THE PLATFORMS, SOME DIFFERENCES IN THE BASE STRUCTURE, POSSIBLE IN THE SADDLE AND THE CONNECTION OF THE DRIVES FEM ANALYSES DONE - ALL ANALYSES ON THE GLOBAL MODEL - CHECK OF THE STRESSES IN STEEL SHEETS AND IN THE CFRP - LOADS ON THE MECHANICAL INTERFACES Preparation of a FEM model for a detailed stiffness verification of the azimuth bearing ►IN PROGRESS

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 3 FEM ANALYSES LOAD CONDITIONS - GRAVITY WITH ANTENNA AT 0° ELEVATION AND AT 90° ELEVATION - TRANSPORTER LOADS, ANTENNA AT 90° ELEVATION, FIXED TO THE TRANSPORTER FLANGES, IN ACCORDING WITH THE ICD: - GRAVITY IN X DIRECTION - GRAVITY IN Y DIRECTION - GRAVITY IN Z DIRECTION - 11 WIND-LOAD CASES, WITH THE LOADS FROM THE NEW WIND ANALYSIS - UNIFORM THERMAL GRADIENT - MAXIMUM LIKE EARTHQUAKE

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 4 FEM ANALYSES LOAD COMBINATIONS ACCORDING TO TECHNICAL SPECIFICATION # OPERATIONAL CONDITIONS - GRAVITY + THERMAL + WIND 20m/s - GRAVITY + THERMAL + WIND 6.4m/s + FAST SWITCHING ACCIDENTAL CONDITIONS - GRAVITY + THERMAL + WIND 30m/s + EMERGENCY BRAKING - GRAVITY + WIND 20m/s + TRANSPORTER HANDLING SURVIVAL CONDITIONS - GRAVITY + WIND 65m/s - GRAVITY + THERMAL + WIND 30m/s - GRAVITY + WIND 30m/s + ICING + SNOW - GRAVITY + MLE + WIND 20m/s

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 5 FEM ANALYSES TRANSPORTER HANDLING LOAD CASES According to ICD between ALMA antenna and ALMA antenna transporter TRANSPORT SHOCKS, WITH NORMAL WIND - Wind 25m/s + 1Gx + 1Gy + 2Gz TRANSPORTER IN PARKING POSITION, WITH STRONG WIND - Wind 45m/s + 1Gz TRANSPORTER COLLISION, HORIZONTAL SHOCK, WITH NORMAL WIND IN FORWARD DRIVING DIRECTION - Wind 25m/s + 1Gz + 2Gy SUPPORT POINT FAILURE (one point) TRANSPORTER HANDLING SHOCK (Technical Specification § ) - 4g vertical impact

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 6 FEM ANALYSES TRANSPORTER HANDLING CONSTRAINTS ACCORDING WITH THE ICD GRAVITY IN X DIRECTION MAXIMUM STRESS IN THE ELEVATION MEMBRANES

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 7 FEM ANALYSES WIND ANALYSIS 11 LOAD CASES FROM THE NEW WIND ANALYSIS, CALCULATED WITH v = 9.5m/s - Scaled to v = 9m/s, 20m/s, 25m/s, 30m/s, 45m/s, 65m/s for the operational, accidental and survival conditions THERMAL ANALYSIS UNIFORM THERMAL GRADIENT, dT = 20°C, 30°C, 40°C for the operational, accidental and survival conditions

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 8 FEM ANALYSES STATIC WIND ANALYSIS WIND LOAD CASE 8 – AZ 90° – EL 60° DISPLACEMENTS USUM WITH v = 65m/s WIND LOAD CASE 8 – AZ 90° – EL 60° PRESSURE WITH v = 9.5m/s

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 9 UPDATING OF THE SEISMIC VERIFICATION ► MODAL ANALYSIS ► 50 natural modes were considered up to 35Hz ► 50 further modes were considered up to 50Hz ► Higher frequencies mainly deal with local modes ► SPECTRUM ANALYSIS ►Only the horizontal components of the seismic action have been considered ►A new analysis involving both the horizontal and the vertical response spectrum of the ALMA site (according to ALMA Environmental Specifications) is in progress ►The seismic action is being analysed according to Eurocode 8, by combining its effects in x,y,z directions as follows: a. Ex “+” Ey “+” 0.3Ez b. Ex “+” 0.3Ey “+” Ez c. 0.3Ex “+” Ey “+” Ez

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 10 FEM ANALYSES RESULTS - Displacements of 602 nodes (panels adjusters + primary vertex + secondary vertex) for the error budget - Stress verification - Loads on the mechanical interfaces - AZIMUTH BEARING - ELEVATION BEARINGS (and SHAFTS, MEMBRANES…) - ELEVATION ROLLER GUIDES - Loads on structural interfaces - APEX – LEGS CONNECTIONS - LEGS – BUS CONNECTIONS - BUS – CABIN FLANGES - INTERFACE FLANGES WITH GROUND