Field Measurements for Traffic Noise Reduction in Highway Tunnels Using Closed-Cell Aluminum Foam Board

In order to explore the sound absorption and noise reduction performance of closed-cell aluminum foam in the tunnel, the field test of the sound absorption performance of aluminum foam board was carried out based on the installation of aluminum foam board in the whole line of Haoshanyu Tunnel on Qinglan Expressway. Combined with the existing loudspeaker test and typical tunnel measurements, a new field test method for the noise reduction performance of closed-cell aluminum foam board was proposed for two different working conditions including fixed-point pure tone sound source condition and mobile vehicle sound source condition. The testing results of the new methods were analyzed, and it showed that the closed-cell aluminum foam has good sound absorption property at the frequency spectra between 250 Hz and 1000 Hz, and the farther away from the sound source, the better the sound absorption effect. In the research on the noise reduction effect of actual vehicle, it was found that the insertion loss of the closed-cell foam aluminum board is about 4 dB(A), which indicated that the closed-cell aluminum foam can play a certain noise reduction effect in the tunnel.

Study on Buffering Performance of Aluminum Foam during Water-entry Process

The structure will suffer a huge overload, when it enters into water. The buffer head cap can effectively reduce the overload, and the buffer material in the cap is the key to its load reduction performance. In order to study the buffering ability of aluminum foam, an effective numerical simulation method is established in this paper. The numerical simulation method can effectively observe the motion of the structure and the energy absorption process of aluminum foam. It is found that the aluminum foam has strong capacity of buffering and reducing load by comparing with the structure without buffer head cap under the same conditions. In the process of energy absorption deformation, it can effectively protect the projectile from buckling deformation.

Efficiency Enhancement of Photovoltaic Module Using An Aluminum Foam Matrix Filled With Phase Change Material (PCM) Under Hot Climate Conditions

In the present work, a passive cooling strategy combining an aluminium foam matrix (AFM) with PCM was employed to regulate the temperature of a photovoltaic (PV) system The comparison between three PV modules was established ,the first one was conventional without any changes ,the second one was PV combined with PCM (PV-PCM) and the last one was PV combined with modified PCM which contain an aluminum foam matrix embedded in it (PV-PCM/AFM).Outdoor experiments were carried out in the hot weather of Benha, Egypt, which is situated at latitude 30.466° North and longitude 31.185° East. A comparison of the three PV designs was given and analysed, based on PV surface temperature, PCM temperature, open-circuit voltage, output power generated, and electrical efficiency. It was observed that using composite PCM resulted in better heat absorption from the PV module and better temperature distribution inside the PCM enclosure. Furthermore, the results indicated that against the unmodified PV system, the average cell’s temperature in the PV-PCM system was dropped by 13.3% and its electrical power was enhanced by 9%. Meanwhile, the average cell temperature in the PV-PCM/AFM configuration was reduced by 21.6% while the enhancement of the electrical power was at 14%. Furthermore, the findings demonstrated that, as compared to unmodified PCM, AFM impregnation accelerated the melting of modified PCM by roughly 37%.

Experimental Study on the Impact Resistance of Closed-Cell Aluminum Foam Protective Materials to RC Piers under Lateral Impact

In this study, the lateral impact tests of six RC piers which were protected by closed-cell aluminum foam (CCAF) were carried out by making use of an ultrahigh drop hammer horizontal impact test system. The protective effects of CCAF with different densities on the piers were then analyzed. The data regarding the piers’ impact force, displacement, reinforcement strain, and crack and damage development were mainly collected during the experimental testing processes. The results indicated that, when the impact energy was less than 7258 J and the density of the CCAF was 0.45 g/cm3, the cumulative impact force and displacements of the piers decreased by 67% and 35%, respectively. Therefore, it was considered that the CCAF with a density of 0.45 g/cm3 had displayed the best protective effects at that stage. It was also observed that when the impact energy was greater than 7258 J and the density of the CCAF was 0.55 g/cm3, the cumulative impact force and displacements of the piers decreased by 25% and 18%, respectively. Therefore, the CCAF with a density of 0.55 g/cm3 had displayed the best protective effects at that stage. Furthermore, under the conditions of constant accumulative impact energy, the protective effects of CCAF on the piers were observed to be weakened if it entered the densification stage too early and high-yield platforms were formed due to the density levels becoming too high. However, it was found that reasonable density and thickness increases could effectively delay the entry of CCAF into the densification stage, which effectively reduced the shearing effects which occurred when the impact speeds were too high, thereby preventing the shear failure of the piers.