{"id":558187,"date":"2024-11-05T18:20:18","date_gmt":"2024-11-05T18:20:18","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/esdu-790052010\/"},"modified":"2024-11-05T18:20:18","modified_gmt":"2024-11-05T18:20:18","slug":"esdu-790052010","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/esdu\/esdu-790052010\/","title":{"rendered":"ESDU 79005:2010"},"content":{"rendered":"

INTRODUCTION<\/strong><\/p>\n

The construction techniques employed in modern high-rise
\nbuildings lead to structures of relatively high flexibility and low
\nmass so that the effect of dynamic loads on the structure become
\nincreasingly important. A knowledge of the natural frequency
\nparameters is necessary for the investigation of the response of a
\nbuilding to such loads. The natural frequency parameters, required
\nfor the calculation of the response of a building to fluctuating
\nloads by the modal superposition method, are natural frequencies,
\nmode shapes, and normal-mode generalised masses (or inertias) and
\nstiffnesses. In considering lateral modes, generalised masses and
\nlateral stiffnesses are used and for torsional modes, generalised
\nrotational inertias and rotational stiffnesses are required. The
\nway in which these data are used in the case of the calculation of
\nthe response of a building under the action of a fluctuating wind
\nload is described in the Data Items in Sections 7, 8 and 9.<\/p>\n

This Item provides a means of estimating the natural
\nfrequencies, mode shapes and normal-mode generalised masses* for
\nboth lateral and torsional undamped modes of vibration of shear
\nbuildings. A relationship is given from which the generalised
\nstiffnesses for lateral and torsional modes might be obtained using
\nother data provided. This Item is primarily intended for use with
\nuncoupled modes of vibration although coupling between lateral and
\ntorsional modes is considered in Appendix B where expressions for
\nthe estimation of coupled mode parameters are given for a special
\nclass of shear building.<\/p>\n

The data provided are restricted to use for those buildings that
\nmay be modelled as shear type buildings. A shear building is
\ndefined as a building that has inextensible columns and rigid
\nfloors which prevent joint rotations. In this Item it is assumed
\nthat the reductions in column stiffness due to the axial loads
\napplied by the supported structure are negligible. This stiffness
\neffect causes a reduction in frequency and may modify the mode
\nshapes but is generally small. Further, it is assumed that the
\nbuildings have a rigid base. Thus, by implication, the displacement
\nat ground level is assumed to be zero and it is assumed that no
\nsoil\/structure interaction takes place.<\/p>\n

The mathematical model of the shear building, illustrated in
\nSketch 3.1, is further idealised (as described in Section 4) to
\nprovide a graphical solution for the natural mode of vibration
\nparameters. A computer program is provided in the
\nWind<\/i><\/strong> Engineering Series via
\nthe website<\/strong><\/i> that allows the solution of the shear
\nbuilding model without the necessary further idealisation imposed
\nby the graphical solution. A number of modes of vibration may
\nsignificantly contribute to the dynamic loads on a building
\nalthough it is generally the lowest frequency mode which has the
\ngreatest influence on the dynamic response. Graphical data are
\nprovided for the first four natural modes of vibration for both
\nlateral and torsional oscillations.<\/p>\n

* The terms mass, stiffness and displacement are used in the
\ngeneric sense to include rotational inertia, rotational stiffness
\nand rotational displacement, respectively, for the torsional
\nvibration case.<\/p>\n","protected":false},"excerpt":{"rendered":"

Undamped Natural Vibration of Shear Buildings<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
ESDU<\/b><\/a><\/td>\n2010-08<\/td>\n42<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":558196,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2675],"product_tag":[],"class_list":{"0":"post-558187","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-esdu","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/558187","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/558196"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=558187"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=558187"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=558187"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}