Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as ...Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as shopping malls with subjects that produce serious level of noise and vibrations. Apart to regular use of polyurethane in thermal insulation purposes, it is widely used in field of acoustic insulation. Usage of polyurethane foam pads, with specific dynamic characteristics, as a base for structure supports gives a wide range of possibilities in controlling the amount of structural noise and vibrations transferred to the structure. Structure itself and acoustical pads becomes an integral system that behaves together and need to be analyzed as a whole in extensive design. Dynamic characteristics of acoustic pads depend on stress level and in same time they represent elastic supports to the structure and therefore analyzes and design is an iterative process. In other way, introduce of non-conventional material in bearing structure brings some issues, such as transfer of shear forces, that has to be governed by proper structural detailing. There are several possibilities of application in bearing structures, such as above and below steel structure. This paper gives an overall view on polyurethane as material, construction and design principles and example of usage of acoustic pads in steel structure of＂Ster＂ cineplex in Belgrade.展开更多
A visco-plastic rate-dependent homogenization theory for particle-reinforced composites was derived and the equivalent elastic constants and the equivalent visco-plastic parameters of these composites were obtained. A...A visco-plastic rate-dependent homogenization theory for particle-reinforced composites was derived and the equivalent elastic constants and the equivalent visco-plastic parameters of these composites were obtained. A framework of homogenization the- ory for particle-reinforced W-Ni-Fe composites, a kind of tungsten alloy, was established. Based on the homogenization theory and a fixed-point iteration method, a unit cell model with typical microstructnres of the composite was established by using dynamic analysis program. The effects of tungsten content, tungsten particle shape and particle size and interface strength on the mechanical properties and the crack propagation of the W-Ni-Fe composite are analyzed under quasi-static and dynamic loadings. The stress-strain curves of the composite are given and the relation between the macro-mechanical characteristics and the microstructure parameters is explored, which provides an important theoretical basis for the optimization of the W-Ni-Fe composites.展开更多
文摘Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as shopping malls with subjects that produce serious level of noise and vibrations. Apart to regular use of polyurethane in thermal insulation purposes, it is widely used in field of acoustic insulation. Usage of polyurethane foam pads, with specific dynamic characteristics, as a base for structure supports gives a wide range of possibilities in controlling the amount of structural noise and vibrations transferred to the structure. Structure itself and acoustical pads becomes an integral system that behaves together and need to be analyzed as a whole in extensive design. Dynamic characteristics of acoustic pads depend on stress level and in same time they represent elastic supports to the structure and therefore analyzes and design is an iterative process. In other way, introduce of non-conventional material in bearing structure brings some issues, such as transfer of shear forces, that has to be governed by proper structural detailing. There are several possibilities of application in bearing structures, such as above and below steel structure. This paper gives an overall view on polyurethane as material, construction and design principles and example of usage of acoustic pads in steel structure of＂Ster＂ cineplex in Belgrade.
基金supported by the National Natural Science Foundation of China (Grant No. 11032002 and 91016013)the program for New Century Excellent Talents in University+1 种基金National Basic Research Program of China (Grant No. 2010CB832706)the project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology)(Grant No. ZDKT10-03a)
文摘A visco-plastic rate-dependent homogenization theory for particle-reinforced composites was derived and the equivalent elastic constants and the equivalent visco-plastic parameters of these composites were obtained. A framework of homogenization the- ory for particle-reinforced W-Ni-Fe composites, a kind of tungsten alloy, was established. Based on the homogenization theory and a fixed-point iteration method, a unit cell model with typical microstructnres of the composite was established by using dynamic analysis program. The effects of tungsten content, tungsten particle shape and particle size and interface strength on the mechanical properties and the crack propagation of the W-Ni-Fe composite are analyzed under quasi-static and dynamic loadings. The stress-strain curves of the composite are given and the relation between the macro-mechanical characteristics and the microstructure parameters is explored, which provides an important theoretical basis for the optimization of the W-Ni-Fe composites.
