Generating source of standardized impact: construction and qualification

Author(s)

Roberto Mojolla

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Civil, Arquitetura e Urbanismo
• Defense date: 2015-02-13

Examining board members

Stelamaris Rolla Bertoli; Marcos Antonio Porta Saramago; Maria de Fatima Ferreira Neto

• Advisor: Stelamaris Rolla Bertoli

Abstract

One of the most frequent complaints among inhabitants of residential buildings is the annoyance caused by noise impacts in the floor-ceiling systems resulting from walking or falling objects. According to national and international standards, assess the acoustic performance of these systems depends on the use of standardized and certified equipment. To meet the methods of assessing the acoustic performance suggested by the standards it is necessary to import most of the recommended equipment, causing disturbances of several orders. Assessment of acoustic insulation flooring subjected to impacts depends on use of a standardized source of impacts (Standard Tapping Machine). This is the standard equipment for floors excitation in the evaluation of sound pressure level impacts. The NBR 15575-3 (2013) indicates the use of the method of measurement and evaluation of acoustic performance levels with respect to noise impacts proposed by the ISO 140-7 (1998) and ISO 717-2 (2013). In Annex A of ISO 140-7 (1998) the features and functions are described that the machine must meet standardized impacts. This research aimed to construct and qualify to use a sound source of standardized impacts. For construction of the source, checking the indications in Annex A of ISO 140-7 (1998), the component parts of the equipment are designed, made and assembled. To qualify the prototype of the source were carried out measures in the field of sound pressure level of impact in floor-ceiling shared systems in buildings, as recommended by the standard 15575-3 (2013), using a commercial impact machine and repeating the procedure with the prototype built. Comparison of sound pressure levels of standardized impacts, obtained as a function of frequency, numerically validated the use of the prototype in measurements performed in the field. These measurements quantify and qualify the sound insulation provided by floor-ceiling systems tested with respect to the impact of noise. Innovations were incorporated into the prototype through the adoption of linear bearings as guides for the fall of the hammers and the inclusion of resilient pieces on the numbered elevation of hammers, reducing the emission of airborne noise operation (AU)

• FAPESP's process: 12/14487-6 - Standardized Impact Noise Generating Source: Building and Qualification.
• Grantee: Roberto Mojolla
• Support Opportunities: Scholarships in Brazil - Master