{"id":269,"date":"2014-09-05T10:32:07","date_gmt":"2014-09-05T10:32:07","guid":{"rendered":"http:\/\/lpms.dicam.unitn.it\/?page_id=269"},"modified":"2014-09-05T10:40:37","modified_gmt":"2014-09-05T10:40:37","slug":"footbridge-monitoring","status":"publish","type":"page","link":"https:\/\/lpms.dicam.unitn.it\/?page_id=269","title":{"rendered":"Footbridge Monitoring"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"color: #000000;\">The Laboratory of Testing Materials and Structures (LPMS) operates, for the benefit of private and public administrations, in the contexts of the dynamic structural identification and Structural Health Monitoring (SHM).<\/span><\/p>\n<p><span style=\"color: #ff0000;\"><b>Footbridge dynamic behaviour<\/b><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">Footbridges frequently show high amplitude oscillations due to their structural complexity and their lightness and flexibility.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">In order to evaluate the dynamic behaviour of a structure LPMS execute dynamic identification tests and SHM.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">According to the dynamic behaviour recorded in acquisitions and their interpretation, the design of damping devices could be necessary. Typically the structural analysis and design of such devices is performed by means of a numerical model of the structure tuned on the basis of experimental results (process model up-dating, see Figure 1).<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_1.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-241\" alt=\"Monitoraggio_passerelle_pedonali_1\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_1.jpg\" width=\"500\" height=\"167\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_1.jpg 500w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_1-300x100.jpg 300w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\" align=\"center\"><span style=\"color: #008000;\">Figure 1: San Michele footbridge: design of a Tuned Mass Damper based on structural dynamic identification and model up-dating<\/span><\/p>\n<p><span style=\"color: #ff0000;\"><b>Dynamic Identification<\/b><\/span><\/p>\n<p>LPMS performs the following types of tests:<\/p>\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 20px;\">\n<ul style=\"padding-left: 20px;\">\n<li style=\"line-height: 1.5em; padding-left: 10px;\">Simple Input Multi Output (SIMO) forced vibration tests, using a shaker (SST), an instrumented hammer (Impact hammer test) (see as an example Figure 2) or an external force acquired with a load cell (Snap off test);<\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\">Ambient Vibration Test (AVT): exploiting environmental vibrations in situ (wind or traffic) to characterize the structure dynamics;<\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\">Pedestrian excitation tests as shown in Figure 3<\/li>\n<\/ul>\n<\/ul>\n<\/ul>\n<\/ul>\n<p style=\"text-align: center;\">\n<p style=\"text-align: center;\"><span style=\"color: #008000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_10.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-270\" alt=\"Monitoraggio_passerelle_pedonali_10\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_10.jpg\" width=\"213\" height=\"285\" \/><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #008000;\">Figure 2:\u00a0Impact hammer test<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_3.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-245\" alt=\"Monitoraggio_passerelle_pedonali_3\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_3.jpg\" width=\"204\" height=\"273\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #008000;\">Figure 3:\u00a0Pedestrian excitation test<\/span><\/p>\n<p><span style=\"color: #000000;\">Tests are commonly performed using the following tools:\u00a0<\/span><\/p>\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 20px;\">\n<ul style=\"padding-left: 20px;\">\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">PCB Piezoelectric accelerometers model 352C33, 393C, A03 and B12, sensitivity range 100 mV\/g -10 V\/g in order to optimize the instrumental resolution in function of vibration amplitude to be acquired;<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">PCB Impact hammer model 086D50;<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">ElectroSEIS Electromechanical shaker model 400 and relevant amplifiers<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">Load cells;<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">3 data acquisition NI 4472-B, 24 channels<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">data acquisition program (in LabView);\u00a0<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">digital function generator;\u00a0<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">2 km coaxial cables with BNC connectors<span style=\"line-height: 1.5em;\">\u00a0<\/span><\/span><\/li>\n<\/ul>\n<\/ul>\n<\/ul>\n<\/ul>\n<p style=\"text-align: justify;\">\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">Preliminarily the execution of the dynamic tests, LPMS analyses the best instrument lay-out, typically by verifying the MAC matrix related to measuring points and frequencies of structural interest, as shown in Figure 4.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">Through the use of various type of algorithms and in function of the category of performed test, it is possible to identify the frequencies and mode shapes of the structural interest. Figure 5 reports an example of identified frequency and related mode shape.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000; line-height: 1.5em;\">\u00a0<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_4.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-246\" alt=\"Monitoraggio_passerelle_pedonali_4\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_4.jpg\" width=\"214\" height=\"198\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_5.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-247\" alt=\"Monitoraggio_passerelle_pedonali_5\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_5.jpg\" width=\"643\" height=\"318\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_5.jpg 643w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_5-300x148.jpg 300w\" sizes=\"auto, (max-width: 643px) 100vw, 643px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #008000;\">Figure 4:\u00a0San Michele all\u2019Adige footbridge: analysis of instruments layout in order to identify the dynamic behavior<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_6.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-248\" alt=\"Monitoraggio_passerelle_pedonali_6\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_6.jpg\" width=\"612\" height=\"211\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_6.jpg 612w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_6-300x103.jpg 300w\" sizes=\"auto, (max-width: 612px) 100vw, 612px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #008000;\">Figure 5:\u00a0San Michele all\u2019Adige footbridge: frequency and mode shape identification<\/span><\/p>\n<p><span style=\"color: #ff0000;\"><b>Structural Health Monitoring<\/b><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #000000;\">The LPMS can monitor the static and dynamic behaviour of a structure using the combined acquisition of signals with low sampling frequency (static) (typically in the range 10<sup>-4<\/sup>-1 Hz &#8211; Figure 7) and high frequency (dynamic) signals (typically 10<sup>2<\/sup>-10<sup>3<\/sup> Hz &#8211; Figure 6). With respect to static acquisitions LPMS offers anemometers, thermometers, hygrometer, inclinometers, strain gauges, displacement transducers (inductive, potentiometric and strain gauges). Dynamics acquisitions commonly are performed with the use of accelerometers<\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_7.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-250\" alt=\"Monitoraggio_passerelle_pedonali_7\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_7.jpg\" width=\"598\" height=\"292\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_7.jpg 598w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_7-300x146.jpg 300w\" sizes=\"auto, (max-width: 598px) 100vw, 598px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><span style=\"color: #008000;\">Figure 6:\u00a0Nomi-Calliano footbridge: accelerometer arrangement in the permanent monitoring system<\/span><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_8.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-251\" alt=\"Monitoraggio_passerelle_pedonali_8\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_8.jpg\" width=\"665\" height=\"207\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_8.jpg 665w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_8-300x93.jpg 300w\" sizes=\"auto, (max-width: 665px) 100vw, 665px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #000000;\"><a href=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_9.jpg\"><span style=\"color: #000000;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-252\" alt=\"Monitoraggio_passerelle_pedonali_9\" src=\"http:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_9.jpg\" width=\"559\" height=\"227\" srcset=\"https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_9.jpg 559w, https:\/\/lpms.dicam.unitn.it\/wp-content\/uploads\/2014\/09\/Monitoraggio_passerelle_pedonali_9-300x121.jpg 300w\" sizes=\"auto, (max-width: 559px) 100vw, 559px\" \/><\/span><\/a><\/span><\/p>\n<p style=\"text-align: center;\"><span style=\"color: #008000;\">Figure 7:\u00a0Nomi-Calliano footbridge: arrangement of thermometers and anemometers<\/span><\/p>\n<p><span style=\"color: #ff0000;\"><b>Activities<\/b><\/span><\/p>\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 40px;\">\n<ul style=\"padding-left: 20px;\">\n<ul style=\"padding-left: 20px;\">\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\"><span style=\"color: #000000;\">Ponte del Mare (Pescara):\u00a0<\/span><\/span><span style=\"line-height: 1.5em;\">Dynamic identification and SHM<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">San Michele all\u2019Adige footbridge (TN):\u00a0Dynamic identification<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">Nomi-Calliano footbridge (TN):\u00a0Dynamic identification and SHM<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">Torre eolica presso l\u2019Interporto di Trento (TN): \u00a0Dynamic identification<\/span><\/li>\n<li style=\"line-height: 1.5em; padding-left: 10px;\"><span style=\"color: #000000;\">Campanile di Portogruaro:\u00a0Dynamic identification and SHM<\/span><\/li>\n<\/ul>\n<\/ul>\n<\/ul>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>The Laboratory of Testing Materials and Structures (LPMS) operates, for the benefit of private and public administrations, in the contexts of the dynamic structural identification and Structural Health Monitoring (SHM). Footbridge dynamic behaviour Footbridges frequently show high amplitude oscillations due to their structural complexity and their lightness and flexibility. In order to evaluate the dynamic [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-269","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/pages\/269","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=269"}],"version-history":[{"count":4,"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/pages\/269\/revisions"}],"predecessor-version":[{"id":274,"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=\/wp\/v2\/pages\/269\/revisions\/274"}],"wp:attachment":[{"href":"https:\/\/lpms.dicam.unitn.it\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=269"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}