摘要:
A structurally efficient rod-stiffened panel incorporating pretressing benefits is provided, the prestress provided by pultruded rod which is already in the system. The pultruded rods being retained in either tension or compression stresses apply prestressing via interfacial behavior. The new system improves the efficiency of structural composites by tailoring the stress system within structure to fully utilize the structural potential of various components, and to avoid premature local failures within composite structures. A method for producing a prestressed rod stiffened composite structure is also provided.
摘要:
A method of joining two articles through a nano-enhanced joining medium is described. Nanomaterials are applied to the surfaces of sheets made of the joining medium via casting or spraying. Said sheets with nanomaterial coatings are then placed between the joining surfaces of the articles, and then application of pressure and heating is used to form a nano-engineered structural joint at the interface of said articles. The distinctly high specific surface area of nanomaterials and the energetic preference of their functionalized surfaces for bonding facilitate the joining process. Nano-engineered structural joints complement high strength levels with desired toughness and the compliance needed for accommodating deformation (e.g. thermal expansion) mismatches of joined articles without generating high stress levels near their interface. The limited quantity (per unit joint surface area) of nanomaterials utilized in nano-engineered joints benefits their economic viability.
摘要:
A method of joining two articles through a nano-enhanced joining medium is described. Nanomaterials are applied to the surfaces of sheets made of the joining medium via casting or spraying. Said sheets with nanomaterial coatings are then placed between the joining surfaces of the articles, and then application of pressure and heating is used to form a nano-engineered structural joint at the interface of said articles. The distinctly high specific surface area of nanomaterials and the energetic preference of their functionalized surfaces for bonding facilitate the joining process. Nano-engineered structural joints complement high strength levels with desired toughness and the compliance needed for accommodating deformation (e.g. thermal expansion) mismatches of joined articles without generating high stress levels near their interface. The limited quantity (per unit joint surface area) of nanomaterials utilized in nano-engineered joints benefits their economic viability.
摘要:
Method of joining articles using microscale brazing alloy particles reinforced with slender nanomaterials is described. Surface modified graphite nanomaterials were dispersed in a medium comprised of metal alloy particles, this dispersion was introduced at the interface between the joining articles followed by heating under ultra high vacuum. The nanomaterial-to-metal alloy surface contacts were enhanced by at least one of fusion, embedment and chemical reaction phenomena under high temperature and ultra high vacuum yielding true nanocomposite at the interface. The fusion, embedment and chemical reaction phenomena enhance at least one of the mechanical, electrical, thermal, durability and functional attributes of these contact points, which translate into improved properties of the joined article. The enhanced contact points enable effective use of the distinct qualities of nanomaterials towards development of joints which offer unique balances of strength, ductility, toughness, energy absorption, thermal stability, weathering resistance and other characteristics.
摘要:
Method of joining articles using microscale brazing alloy particles reinforced with slender nanomaterials is described. Surface modified graphite nanomaterials were dispersed in a medium comprised of metal alloy particles, this dispersion was introduced at the interface between the joining articles followed by heating under ultra high vacuum. The nanomaterial-to-metal alloy surface contacts were enhanced by at least one of fusion, embedment and chemical reaction phenomena under high temperature and ultra high vacuum yielding true nanocomposite at the interface. The fusion, embedment and chemical reaction phenomena enhance at least one of the mechanical, electrical, thermal, durability and functional attributes of these contact points, which translate into improved properties of the joined article. The enhanced contact points enable effective use of the distinct qualities of nanomaterials towards development of joints which offer unique balances of strength, ductility, toughness, energy absorption, thermal stability, weathering resistance and other characteristics.
摘要:
A method of joining two articles using slender nanomaterials is described. Randomly oriented nanomaterial mats or aligned nanomaterial arrays are introduced at the interface between the two articles followed by their energization via at least one of microwave irradiation and heating. The nanomaterial-to-nanomaterial and nanomaterial-to-surface contacts are enhanced by at least one of fusion, embedment and chemical reaction phenomena upon energization. The fusion, embedment and chemical reaction phenomena enhance at least one of the mechanical, electrical, thermal, durability and functional attributes of these contact points, which translate into improved properties of the joined article. The enhanced contact points enable effective use of the distinct qualities of nanomaterials towards development of joints which offer unique balances of strength, ductility, toughness, transport qualities, thermal stability, weathering resistance and other characteristics.
摘要:
Ultra-high-performance cementitious materials are made using suitably functionalized and relatively low-cost carbon nanofibers and graphite platelets. Polyelectrolytes and surfactants are physisorbed upon these graphite nanomaterials in water, and dispersion of nanomaterials in water is achieved by stirring. Stable and well-dispersed suspensions of nanomaterials in water are realized without using energy-intensive and costly methods, and also without the use of materials which could hinder the hydration and strength development of ultra-high-performance cementitious materials. The water incorporating dispersed nanomaterials is then mixed with the cementitious matrix and, optionally, microfibers, and cured following standard concrete mixing and curing practices. The resulting cementitious materials incorporating graphite nanomaterials and optionally microfibers offer a desired balance of strength, toughness, abrasion resistance, moisture barrier attributes, durability and fire resistance.
摘要:
Shaped articles with the inherent capability to evolve in response to at least one of external and internal stimuli are described. These articles comprise at least one solid electrolyte with at least one dissolved salt, and at least one interface which involves a solid electrolytes and a conductive solid. Electric potential gradients, generated within the solid electrolyte by at least one of external and internal stimuli, guide and drive the self-healing and adaptation phenomena. The electric potential gradient is generated by at least one of the following effects: (i) direct application of an electric potential across the solid electrolyte; (ii) introduction of interfaces of different electrode potentials between the solid electrolyte and conductive solids; (iii) introduction of an interface between the solid electrolyte and a conductive solid embodying atoms of lower ionization energy than at least one of the atoms forming the ions of the dissolved salt in solid electrolyte; (iv) application of external load and environmental effects which, either directly or when interacting with defects developed in the article during manufacturing and use, generate stress and temperature gradients which, in turn, produce or magnify the potential gradients between the interfaces with solid electrolyte. The mechanisms through which the electric potential gradient generated by different stimuli bring about changes in article performance involve migration of ions and their electrodeposition within the solid electrolyte and at interfaces.
摘要:
Ultra-high-performance cementitious materials are made using suitably functionalized and relatively low-cost carbon nanofibers and graphite platelets. Polyelectrolytes and surfactants are physisorbed upon these graphite nanomaterials in water, and dispersion of nanomaterials in water is achieved by stirring. Stable and well-dispersed suspensions of nanomaterials in water are realized without using energy-intensive and costly methods, and also without the use of materials which could hinder the hydration and strength development of ultra-high-performance cementitious materials. The water incorporating dispersed nanomaterials is then mixed with the cementitious matrix and, optionally, microfibers, and cured following standard concrete mixing and curing practices. The resulting cementitious materials incorporating graphite nanomaterials and optionally microfibers offer a desired balance of strength, toughness, abrasion resistance, moisture barrier attributes, durability and fire resistance.
摘要:
Shaped articles with the inherent capability to evolve in response to at least one of external and internal stimuli are described. These articles comprise at least one solid electrolyte with at least one dissolved salt, and at least one interface which involves a solid electrolytes and a conductive solid. Electric potential gradients, generated within the solid electrolyte by at least one of external and internal stimuli, guide and drive the self-healing and adaptation phenomena. The electric potential gradient is generated by at least one of the following effects: (i) direct application of an electric potential across the solid electrolyte; (ii) introduction of interfaces of different electrode potentials between the solid electrolyte and conductive solids; (iii) introduction of an interface between the solid electrolyte and a conductive solid embodying atoms of lower ionization energy than at least one of the atoms forming the ions of the dissolved salt in solid electrolyte; (iv) application of external load and environmental effects which, either directly or when interacting with defects developed in the article during manufacturing and use, generate stress and temperature gradients which, in turn, produce or magnify the potential gradients between the interfaces with solid electrolyte. The mechanisms through which the electric potential gradient generated by different stimuli bring about changes in article performance involve migration of ions and their electrodeposition within the solid electrolyte and at interfaces.