Heavy Impact Sources Research Articles

Study on compatibility of reduction transmitted impact sound of dry-type floating floor due to car-tire source and rubber ball source

In Japan, JIS A 1418-2:2019 specifies the car-tire with impact force characteristics (1) and the rubber ball with impact force characteristics (2) as standard heavy impact sources. It has also been reported that the reduction of transmitted impact sound for a dry-type floating floor differs depending on the impact sources of the car-tire and the rubber ball. It has been reported that one of the reasons for different reduction of transmitted impact sound is excessive the car-tire impact force, and a tendency for a nonlinear response to impact force for a dry-type floating floor. Meanwhile in inter.noise 2022, It was also suggested that the reduction of transmitted floor impact sound level of the rubber ball could be estimated from the reduction of transmitted floor impact sound level of the car-tire by considering excitation frequency characteristics. In this paper, a consideration was conducted using the impact force exposure level of the impact source as a method of correcting the excitation frequency characteristics. Also, the results on the comparison of reduction transmitted impact sound using the A-weighted sound pressure level are described.

Reduction of transmitted impact sound of dry-type floating floor due to differences in impact force characteristics

In Japan, JIS A 1418-2:2019 specifies the car-tire with impact force characteristics (1) and the rubber ball with impact force characteristics (2) as standard heavy impact sources. In addition, JIS A 1440-2:2007 specifies the measurement method of the reduction of transmitted impact sound by floor coverings on a solid standard floor. It has also been reported that the reduction of transmitted impact sound differs depending on the impact sources of the car-tire and the rubber ball. It has been reported that one of the reasons for different reduction of transmitted impact sound is excessive car-tire impact force, and a tendency for a nonlinear response to impact force for a dry-type floating floor. In this study, an experimental examination is conducted to interconvert the reduction of transmitted impact sound of the car-tire and the rubber ball. This paper discusses the reduction of transmitted impact sound due to the change in impact force by varying the drop height of the car-tire and the rubber ball. The results suggest that the difference in reduction of transmitted impact sound between the car-tire and the rubber ball cannot be explained only by nonlinearity due to the impact force for a dry-type floating floor.

Countermeasures against floor impact sound by heavy impact source of a box floor structure in a reinforced concrete wall construction testing device

We have performed experimental examinations for the purpose of proposing a floor finishing structure with superior effects in terms of combating heavy-weight floor impact sound. We have developed a box floor with ease of construction and excellent heavy-weight floor impact sound insulation performance and examined its effect with a 1200 × 1200 mm test piece connected to inter-noise 2020. The box floor has a floor finishing structure with anti-vibration and sound insulation measures aimed at improving measures against heavy-weight floor impact sound. We herein report the results of a basic examination on the reduction of the transmitted heavy-weight floor impact sound of a box floor structure in a reinforced concrete wall construction testing device when the area is further expanded to about 10 . As a result, with the air layer under the box floor open, the floor impact sound level was reduced by 9 dB in the 63-Hz band compared to the bare surface. In addition, with the air layer at the bottom of the BOX floor sealed, the floor impact sound level was reduced by 5 dB in the 63-Hz band compared to the bare surface.

Research work of Prof. Tomita, including: 1. Examination of environmental vibration measurement using vibration control rubber on carpet. 2. Measures against floor impact sound by heavy-impact source using storage furniture with tatami. 3. Study on tatami mat considering safety when falling in case of falling collision and sound insulation performance. 4. Research on evaluation method and evaluation rank for vertical

A tatami is a type of mat used as a floor material in many rooms in Japan. They are also used in training rooms, such as in a dojo or martial arts, and are often covered with woven straw. Tatami mats were used as flooring materials for buildings in the Kamakura period (c. 1185) and have a long history. Tatami is often used in the Japanese-style room of today's homes. Generally, tatami mats are 55 mm thick; some mats are made of mostly straw and some made of insulation board and extruded polystyrene foam. The surface of both types of mats is covered with tatami facing. More recently, tatami mats made of insulation board and extruded polystyrene foam are used in homes. Despite their presence in Japanese buildings, there are several problems associated with tatami mats and other floor materials. One of the potential problems concerns the safety of individuals who fall on the mats, while another is the sound created by impact on the mats, such as when people walk or run across them. Research is underway to find effective ways of improving the sound insulation performance of floor materials at the same time as considering the safety of the inhabitants of the buildings with the mats in them. One team, which is investigating means of improving tatami mats and the materials used to build them, is based at the College of Science and Technology in Nihon University, Japan. Led by Professor Ryuta Tomita, the team is engaged with several projects revolving around overcoming heavy-weight floor impact sound insulation performance and safety of individuals who fall on tatami mats.

Experimental determination of transient structure-borne sound power from heavy impact sources on heavyweight floors with floating floors using an inverse form of transient statistical energy analysis

For heavy impacts on floors in heavyweight buildings, prediction models are needed at the design stage to estimate the spatial-average Fast time-weighted maximum sound pressure level in the receiving room. This paper extends previous work using Transient Statistical Energy Analysis (TSEA) in heavyweight buildings by introducing an inverse form of TSEA (ITSEA) to determine the transient structure-borne sound power input from heavy impact sources into a heavyweight base floor with a floating floor. The difference in the power input with and without a floating floor gives a correction factor that can be used to modify the power input into the base floor. This allows the effect of the floating floor to be incorporated in a TSEA model of a heavyweight building. ITSEA is initially validated with heavy impacts from a rubber ball directly onto a concrete base floor and with small, locally reacting, mass-spring systems. Laboratory experiments are then used to quantify the transient structure-borne sound power input into a full-size concrete base floor when a heavy impact is applied to the base floor, and to the base floor with a full-size Ondol floating floor. The resulting TSEA model shows close agreement with the predicted change in the Fast time-weighted maximum sound pressure level due to the floating floor.

Method for evaluating and predicting noise from hard, heavy impact sources

Noise and vibration from activity in fitness facilities, in particular, drops of hard heavy weights, is a common source of disturbance and complaint in residential, commercial, and mixed-use building types. Mitigating systems exist, including specially designed rubber flooring tiles and products for architectural vibration isolation systems, but in the United States, there is no standardized method for evaluating the reduction in noise or vibration provided by these products and systems. Quantitative and comparable data of the effectiveness of these products are therefore lacking. The authors previously reported (Internoise 2015, Noise-Con 2016, ASA Boston 2017) a preliminary test method to evaluate athletic tile flooring with heavy weight drops, based on the reduction in floor vibration (delta-LV) achieved due to the insertion of the products. Preliminary results indicated that the delta-LV measurement adequately described the impact reduction due to athletic tile, over a certain frequency range, reasonably independent of structure. This paper continues the research and further refines the measurement method, verifies its use for designing fitness facilities, and examines additional parameters that may affect measuring and evaluating hard, heavy weight impacts.

Considerations for the evaluation of impact sound from heavy impact sources in adjacent spaces

The ability to limit a sound heard by a neighboring tenant in a mixed-use facility can be achieved by understanding how to control the source of the sound or affect its path. It is also important to evaluate or measure the sound in a way that considers what a tenant might hear. These aspects will be considered when studying impact sound resulting from the drop of heavy impact sources in adjacent spaces.

初期構造計画のための床スラブ内平均重量床衝撃音遮断性能の簡易予測法

Prediction of floor impact sound from a heavy impact source is necessary for the structural design of apartment buildings. However, this is generally impossible to achieve for each room in the building because the room layout has yet to be decided at the structural design stage. As a statistical approach to this problem, we propose average floor impact sound pressure levels as evaluation measures for the structural design of apartment buildings. This is the average value for all rooms that can be located on a concrete slab surrounded by beams. We used two types of single-number quantity; the A-weighted impact sound pressure level (JIS A 1419-2) generated by a rubber ball (JIS A 1418-2) and the impact sound pressure level (L-number) (JIS A 1419-2) generated by a small automobile tire (JIS A 1418-2). Average floor impact sound pressure levels were calculated using the finite element method under conditions where the slab size ranged from 4×4 meters to 8×16 meters with various thicknesses. Then, the relationship between the average floor impact sound pressure level and the size of the concrete slab was examined. It was found that the average floor impact sound pressure level tends to increase with a decrease in slab size. Furthermore, average A-weighted impact sound pressure levels and the logarithm of first natural frequencies of the slab were proportional for slabs of constant thickness. On the other hand, the average L-number is affected by not only first natural frequencies, but also second and third natural frequencies. From the results, simple formulas were derived to predict average floor impact sound pressure levels from lower natural frequencies, the thickness of the slabs, and some corrections.

集合住宅の居住者反応からみた重量床衝撃音遮断性能の生活実感による表現方法の検討

We performed questionnaire survey of the resident awareness about the sound environment for the resident of multi-family housing. We obtained 784 valid response numbers of questionnaires votes. We analyzed the questionnaire survey from various angles. As a result, we obtained the following conclusion. (1)For the floor impact sound by heavy impact source, an evaluation method by the L-class is resident awareness to support well. (2) Resident judgment concerning of degree you hear - degree anxious - degree of noisiness - degree of problem consciousness - degree of satisfaction were shown. (3) For the expression method of the actual feeling on living, it should use the plural items in cluding "degree to hear" and "the indication rate"

Floor Impact Sounds by Heavy Impact Source in Steel Structure Buildings

Floor Impact Sounds by Heavy Impact Source in Steel Structure Buildings

Prediction of the Blocked Force at Impact of Japanese Rubber Ball Source

Characterizing and rating the impact sound isolation of floors and of building structures are important issues in building acoustics. In all standardized test procedures a floor specimen is excited structurally with a standardized impact source and the sound pressure level due to the impact is measured in an adjacent room. Existing standards define several impact sources that should simulate the excitation due to persons walking or jumping on the floor and hence exert only normal forces to the structure. However, the excitation spectrum of the most commonly used lightweight tapping according to ISO 140-7 differs significantly from the heavy impact sources according to JIS A 1418-2 (the rubber ball and the bang machine that are dropped from a defined height to the floor). In order to accurately predict the impact sound isolation of floor assemblies, the excitation mechanism due to impacts from these heavy sources has to be understood and implemented in prediction models. This paper presents a simple analytical model for the rubber ball heavy impact source and the suitability of the model is gauged by comparing the predicted blocked force with experiment.

Laboratory Measurement of Reduction of Transmuted Impact Sound by Floor Coverings on Concrete Standard Floor Using Standard Heavy Impact Sources

Laboratory Measurement of Reduction of Transmuted Impact Sound by Floor Coverings on Concrete Standard Floor Using Standard Heavy Impact Sources

RESIDENT AWARENESS AND OCCUPANCY BEHAVIOR FOR SOUND ENVIRONMENT IN MULTI-FAMILY HOUSING

We did a questionnaire for residents in multi-family housing on resident awareness, supplier's explanation and occupancy behavior concerning sound environment. We obtained 784 valid response numbers of questionnaires votes. We analyzed the questionnaire survey from various angles, As a result, we obtained the following conclution.(1) The dissatisfaction of "floor impact sound insulation performance using heavy impact source" in sound environment is still high.(2) The effect of a prior explanation by the housing supplier is not seen about the resident awareness of "Floor impact sound".(3) It is accepted to the resident to receive the restriction to the way of living multi-family housing as "Manners".

床衝撃音レベルの評価指標及び主観評価との対応に関する研究

We experimented rating of impact sound pressure level by hearing impression with floor impact sound including life sound. And we select the best evaluation index that has a high correlation in hearing impression. As the result, it is shown that maximum A-weighted impact sound pressure level LA,Fmax is better for heavy impact source than L-Number, and arithmetic average of sound pressure levels in octave bands L (63-4k) is better for light impact source than L-Number. Next, we examined the correspondence of LA, Fmax, L (63-4k) and hearing impression.

완충재 유무에 따른 표준중량충격원에 의한 콘크리트 바닥 구조의 소음 및 진동 특성

The characteristics of noise and vibration by a heavy impact source was studied. The triggering method was used for increasing the reliability and stability to measure the level of sound pressure. sound intensity and vibration acceleration. A simple finite element model and a rigid body analysis method were suggested to calculate the natural frequencies of the multi-layer floor system. The results show that the resilient materials decrease the natural frequency of the reinforced concrete slab, make a resonance with dominant driving frequency in the low frequency region, and increase the vibration and noise level. A simple finite element model and rigid body models was suggested to calculate the natural frequencies of the floor systems.

Development of standard heavy impact source for measurement of floor impact sound.

Development of standard heavy impact source for measurement of floor impact sound.

Development of New Standard Heavy Impact Source for Floor Impact Sound

Development of New Standard Heavy Impact Source for Floor Impact Sound

床衝撃音測定用標準重量衝撃源の開発

JIS A 1418-2, which provides the measurement method of floor impact sound by standard heavy impact source, was vastly revised in January, 2000. It provides about the ball which has the different characteristic of impact force(II) from the tire before now. However, there has been a problem that big change of impact force by the ambient temperature, because the development has been executed for the ball made of rubber before now. Then, we tried to make the ball made of silicone-rubber, and examined the reasonability of heavy impact source from the point of view of impact force characteristic and floor impact sound.

Amendment of measurement of floor impact sound insulation performance and proposal of new heavy impact source.

Amendment of measurement of floor impact sound insulation performance and proposal of new heavy impact source.

Proposal for a standard heavy impact source for the measurement of floor impact sound insulation performance

The floor impact sound generated in multifamily dwellings frequently has a peak in the low-frequency band (20–30 Hz). Because of that, in order to assess the floor impact sound insulation performance in real-life situations, it is necessary to measure floor impact sound using a standard impact source, with an impact force characteristic corresponding to actual impact sources. However, in the current ISO standards, a ‘‘tapping machine’’ that is light and stiff with a weak impact force is the only one that has been approved as a standard floor impact source, which cannot be considered adequate as a method of measurement in solving problems of floor impact sound. Actual case examples of the measurement of impact force performance of floor impact sources generated in actual housing units are presented in this paper, together with a verification of the usefulness of the heavy floor impact source stipulated by current JIS standards in Japan and a proposal for the introduction of the same impact force characteristics as ISO standards.