Misplaced Pages

X-bracing

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and joints' that create the form and shape of human-made structures . Structural engineers also must understand and calculate the stability , strength, rigidity and earthquake-susceptibility of built structures for buildings and nonbuilding structures . The structural designs are integrated with those of other designers such as architects and building services engineer and often supervise the construction of projects by contractors on site. They can also be involved in the design of machinery, medical equipment, and vehicles where structural integrity affects functioning and safety. See glossary of structural engineering .

#230769

55-449: X-bracing is a structural engineering practice where the lateral load on a building is reduced by transferring the load into the exterior columns. X-bracing was used in the construction of the 1908 Singer Building , then the tallest building in the world. Some skyscrapers by engineer Fazlur Khan , such as the 1969 John Hancock Center , have a distinctive X-bracing exterior, allowing for both higher performance from tall structures and

110-443: A chartered engineer ). Civil engineering structures are often subjected to very extreme forces, such as large variations in temperature, dynamic loads such as waves or traffic, or high pressures from water or compressed gases. They are also often constructed in corrosive environments, such as at sea, in industrial facilities, or below ground. The forces which parts of a machine are subjected to can vary significantly and can do so at

165-618: A 1922 conference on hydrodynamics and aerodynamics in Innsbruck , Austria, Theodore von Kármán , a Hungarian engineer, and Tullio Levi-Civita , an Italian mathematician, met and decided to organize a conference on applied mechanics. In 1924 the first meeting of the International Congress of Applied Mechanics was held in Delft , the Netherlands attended by more than 200 scientist from around

220-741: A beam (divided along its length) to go into compression and the other part into tension. The compression part must be designed to resist buckling and crushing, while the tension part must be able to adequately resist the tension. A truss is a structure comprising members and connection points or nodes. When members are connected at nodes and forces are applied at nodes members can act in tension or compression. Members acting in compression are referred to as compression members or struts while members acting in tension are referred to as tension members or ties . Most trusses use gusset plates to connect intersecting elements. Gusset plates are relatively flexible and unable to transfer bending moments . The connection

275-431: A catenary in two directions. Structural engineering depends on the knowledge of materials and their properties, in order to understand how different materials support and resist loads. It also involves a knowledge of Corrosion engineering to avoid for example galvanic coupling of dissimilar materials. Common structural materials are: Applied mechanics Applied mechanics is the branch of science concerned with

330-699: A four or five-year undergraduate degree, followed by a minimum of three years of professional practice before being considered fully qualified. Structural engineers are licensed or accredited by different learned societies and regulatory bodies around the world (for example, the Institution of Structural Engineers in the UK). Depending on the degree course they have studied and/or the jurisdiction they are seeking licensure in, they may be accredited (or licensed) as just structural engineers, or as civil engineers, or as both civil and structural engineers. Another international organisation

385-634: A great rate. The forces which a boat or aircraft are subjected to vary enormously and will do so thousands of times over the structure's lifetime. The structural design must ensure that such structures can endure such loading for their entire design life without failing. These works can require mechanical structural engineering: Aerospace structure types include launch vehicles, ( Atlas , Delta , Titan), missiles (ALCM, Harpoon), Hypersonic vehicles (Space Shuttle), military aircraft (F-16, F-18) and commercial aircraft ( Boeing 777, MD-11). Aerospace structures typically consist of thin plates with stiffeners for

440-425: A mature discipline in the U.S. by 1950. Dynamics, the study of the motion and movement of various objects, can be further divided into two branches, kinematics and kinetics . For classical mechanics , kinematics would be the analysis of moving bodies using time, velocities , displacement , and acceleration . Kinetics would be the study of moving bodies through the lens of the effects of forces and masses. In

495-421: A more defined and formalized profession with the emergence of architecture as a distinct profession from engineering during the industrial revolution in the late 19th century. Until then, the architect and the structural engineer were usually one and the same thing – the master builder. Only with the development of specialized knowledge of structural theories that emerged during the 19th and early 20th centuries, did

550-407: A number of relatively simple structural concepts to build complex structural systems . Structural engineers are responsible for making creative and efficient use of funds, structural elements and materials to achieve these goals. Structural engineering dates back to 2700 B.C. when the step pyramid for Pharaoh Djoser was built by Imhotep , the first engineer in history known by name. Pyramids were

605-427: A patient's medical state. Monitors may measure patient vital signs and other parameters including ECG , EEG , blood pressure, and dissolved gases in the blood; diagnostic medical equipment may also be used in the home for certain purposes, e.g. for the control of diabetes mellitus. A biomedical equipment technician (BMET) is a vital component of the healthcare delivery system. Employed primarily by hospitals, BMETs are

SECTION 10

#1732901188231

660-514: A series of failures involving box girders which collapsed in Australia during the 1970s. Structural engineering depends upon a detailed knowledge of applied mechanics , materials science , and applied mathematics to understand and predict how structures support and resist self-weight and imposed loads. To apply the knowledge successfully a structural engineer generally requires detailed knowledge of relevant empirical and theoretical design codes ,

715-476: A structure to move freely with the ground. Civil structural engineering includes all structural engineering related to the built environment. It includes: The structural engineer is the lead designer on these structures, and often the sole designer. In the design of structures such as these, structural safety is of paramount importance (in the UK, designs for dams, nuclear power stations and bridges must be signed off by

770-520: A theoretical foundation based in mathematics was mechanics ; the underlying principles of mechanics were first delineated by Isaac Newton in his 1687 book Philosophiæ Naturalis Principia Mathematica . One of the earliest works to define applied mechanics as its own discipline was the three volume Handbuch der Mechanik written by German physicist and engineer Franz Josef Gerstner . The first seminal work on applied mechanics to be published in English

825-1084: A variety of engineering sub-topics like structural, coastal, geotechnical, construction, and earthquake engineering . In mechanical engineering , it can be applied in mechatronics and robotics , design and drafting, nanotechnology , machine elements, structural analysis, friction stir welding, and acoustical engineering . In aerospace engineering , applied mechanics is used in aerodynamics, aerospace structural mechanics and propulsion, aircraft design and flight mechanics. In materials engineering, applied mechanics’ concepts are used in thermoelasticity, elasticity theory , fracture and failure mechanisms, structural design optimisation, fracture and fatigue, active materials and composites, and computational mechanics. Research in applied mechanics can be directly linked to biomedical engineering areas of interest like orthopaedics; biomechanics; human body motion analysis; soft tissue modelling of muscles, tendons, ligaments, and cartilage; biofluid mechanics; and dynamic systems, performance enhancement, and optimal control. The first science with

880-461: Is IABSE(International Association for Bridge and Structural Engineering). The aim of that association is to exchange knowledge and to advance the practice of structural engineering worldwide in the service of the profession and society. Structural building engineering is primarily driven by the creative manipulation of materials and forms and the underlying mathematical and scientific ideas to achieve an end that fulfills its functional requirements and

935-409: Is a complex non-linear relationship. A beam may be defined as an element in which one dimension is much greater than the other two and the applied loads are usually normal to the main axis of the element. Beams and columns are called line elements and are often represented by simple lines in structural modeling. Beams are elements that carry pure bending only. Bending causes one part of the section of

990-428: Is also divided into two sections: statics and dynamics. Within the practical sciences, applied mechanics is useful in formulating new ideas and theories, discovering and interpreting phenomena, and developing experimental and computational tools. In the application of the natural sciences , mechanics was said to be complemented by thermodynamics , the study of heat and more generally energy , and electromechanics ,

1045-650: Is considered “America’s Father of Engineering Mechanics.” In 1930 Theodore von Kármán left Germany and became the first director of the Aeronautical Laboratory at the California Institute of Technology ; von Kármán would later co-found the Jet Propulsion Laboratory in 1944. With the leadership of Timoshenko and von Kármán, the influx of talent from Europe, and the rapid growth of the aeronautical and defense industries, applied mechanics became

1100-542: Is constructed, and its ability to support the weight of the stone above it. The limestone blocks were often taken from a quarry near the building site and have a compressive strength from 30 to 250 MPa (MPa = Pa × 10 ). Therefore, the structural strength of the pyramid stems from the material properties of the stones from which it was built rather than the pyramid's geometry. Throughout ancient and medieval history most architectural design and construction were carried out by artisans, such as stonemasons and carpenters, rising to

1155-418: Is needed to ensure that the assumed collapse mechanism is realistic. Shells derive their strength from their form and carry forces in compression in two directions. A dome is an example of a shell. They can be designed by making a hanging-chain model, which will act as a catenary in pure tension and inverting the form to achieve pure compression. Arches carry forces in compression in one direction only, which

SECTION 20

#1732901188231

1210-738: Is structurally safe when subjected to all the loads it could reasonably be expected to experience. This is subtly different from architectural design, which is driven by the creative manipulation of materials and forms, mass, space, volume, texture, and light to achieve an end which is aesthetic, functional, and often artistic. The structural design for a building must ensure that the building can stand up safely, able to function without excessive deflections or movements which may cause fatigue of structural elements, cracking or failure of fixtures, fittings or partitions, or discomfort for occupants. It must account for movements and forces due to temperature, creep , cracking, and imposed loads. It must also ensure that

1265-416: Is technically called a beam-column but practically, just a column). The design of a column must check the axial capacity of the element and the buckling capacity. The buckling capacity is the capacity of the element to withstand the propensity to buckle. Its capacity depends upon its geometry, material, and the effective length of the column, which depends upon the restraint conditions at the top and bottom of

1320-418: Is usually arranged so that the lines of force in the members are coincident at the joint thus allowing the truss members to act in pure tension or compression. Trusses are usually used in large-span structures, where it would be uneconomical to use solid beams. Plates carry bending in two directions. A concrete flat slab is an example of a plate. Plates are understood by using continuum mechanics , but due to

1375-473: Is why it is appropriate to build arches out of masonry. They are designed by ensuring that the line of thrust of the force remains within the depth of the arch. It is mainly used to increase the bountifulness of any structure. Catenaries derive their strength from their form and carry transverse forces in pure tension by deflecting (just as a tightrope will sag when someone walks on it). They are almost always cable or fabric structures. A fabric structure acts as

1430-660: The Bolsheviks Red Army in 1918 and eventually emigrated to the U.S. in 1922; over the next twenty-two years he taught applied mechanics at the University of Michigan and Stanford University . Timoshenko authored thirteen textbooks in applied mechanics, many considered the gold standard in their fields; he also founded the Applied Mechanics Division of the American Society of Mechanical Engineers in 1927 and

1485-419: The "Divide and Rule" strategy within dynamic and static studies. Archimedes' principle is a major one that contains many defining propositions pertaining to fluid mechanics. As stated by proposition 7 of Archimedes' principle, a solid that is heavier than the fluid its placed in, will descend to the bottom of the fluid. If the solid is to be weighed within the fluid, the fluid will be measured as lighter than

1540-654: The 1970s. The history of structural engineering contains many collapses and failures. Sometimes this is due to obvious negligence, as in the case of the Pétion-Ville school collapse , in which Rev. Fortin Augustin " constructed the building all by himself, saying he didn't need an engineer as he had good knowledge of construction" following a partial collapse of the three-story schoolhouse that sent neighbors fleeing. The final collapse killed 94 people, mostly children. In other cases structural failures require careful study, and

1595-418: The ability to open up the inside floorplan (and usable floor space) if the architect desires. This engineering-related article is a stub . You can help Misplaced Pages by expanding it . Structural engineering Structural engineering theory is based upon applied physical laws and empirical knowledge of the structural performance of different materials and geometries. Structural engineering design uses

1650-409: The column. The effective length is K ∗ l {\displaystyle K*l} where l {\displaystyle l} is the real length of the column and K is the factor dependent on the restraint conditions. The capacity of a column to carry axial load depends on the degree of bending it is subjected to, and vice versa. This is represented on an interaction chart and

1705-441: The complexity involved they are most often designed using a codified empirical approach, or computer analysis. They can also be designed with yield line theory, where an assumed collapse mechanism is analyzed to give an upper bound on the collapse load. This technique is used in practice but because the method provides an upper-bound (i.e. an unsafe prediction of the collapse load) for poorly conceived collapse mechanisms, great care

X-bracing - Misplaced Pages Continue

1760-465: The context of fluid mechanics, fluid dynamics pertains to the flow and describing of the motion of various fluids. The study of statics is the study and describing of bodies at rest. Static analysis in classical mechanics can be broken down into two categories, deformable bodies and non-deformable bodies. When studying deformable bodies, considerations relating to the forces acting on the rigid structures are analyzed. When studying non-deformable bodies,

1815-578: The creation of the Society of Applied Mathematics and Mechanics, and the first meeting of the International Congress of Applied Mechanics . In 1921 Austrian scientist Richard von Mises started the Journal of Applied Mathematics and Mechanics ( Zeitschrift für Angewante Mathematik und Mechanik ) and in 1922 with German scientist Ludwig Prandtl founded the Society of Applied Mathematics and Mechanics ( Gesellschaft für Angewandte Mathematik und Mechanik ). During

1870-602: The design is practically buildable within acceptable manufacturing tolerances of the materials. It must allow the architecture to work, and the building services to fit within the building and function (air conditioning, ventilation, smoke extract, electrics, lighting, etc.). The structural design of a modern building can be extremely complex and often requires a large team to complete. Structural engineering specialties for buildings include: Earthquake engineering structures are those engineered to withstand earthquakes . The main objectives of earthquake engineering are to understand

1925-451: The examination of the structure and material strength is observed. In the context of fluid mechanics, the resting state of the pressure unaffected fluid is taken into account. Applied Mechanics is a result of the practical applications of various engineering/mechanical disciplines; as illustrated in the table below. Fluid Mechanics Body Applications Engineering Body Engineering Engineering Engineering Being one of

1980-429: The external surfaces, bulkheads, and frames to support the shape and fasteners such as welds, rivets, screws, and bolts to hold the components together. A nanostructure is an object of intermediate size between molecular and microscopic (micrometer-sized) structures. In describing nanostructures it is necessary to differentiate between the number of dimensions on the nanoscale. Nanotextured surfaces have one dimension on

2035-401: The first sciences for which a systematic theoretical framework was developed, mechanics was spearheaded by Sir Isaac Newton's Principia (published in 1687). It is the "divide and rule" strategy developed by Newton that helped to govern motion and split it into dynamics or statics. Depending on the type of force , type of matter , and the external forces, acting on said matter, will dictate

2090-672: The individual structural elements of a structure, such as the beams and columns of a building. More experienced engineers may be responsible for the structural design and integrity of an entire system, such as a building. Structural engineers often specialize in particular types of structures, such as buildings, bridges, pipelines, industrial, tunnels, vehicles, ships, aircraft, and spacecraft. Structural engineers who specialize in buildings may specialize in particular construction materials such as concrete, steel, wood, masonry, alloys and composites. Structural engineering has existed since humans first started to construct their structures. It became

2145-455: The interaction of structures with the shaking ground, foresee the consequences of possible earthquakes, and design and construct the structures to perform during an earthquake. Earthquake-proof structures are not necessarily extremely strong like the El Castillo pyramid at Chichen Itza shown above. One important tool of earthquake engineering is base isolation , which allows the base of

2200-478: The micrometer range. The term 'nanostructure' is often used when referring to magnetic technology. Medical equipment (also known as armamentarium) is designed to aid in the diagnosis, monitoring or treatment of medical conditions. There are several basic types: diagnostic equipment includes medical imaging machines, used to aid in diagnosis; equipment includes infusion pumps, medical lasers, and LASIK surgical machines ; medical monitors allow medical staff to measure

2255-422: The most common major structures built by ancient civilizations because the structural form of a pyramid is inherently stable and can be almost infinitely scaled (as opposed to most other structural forms, which cannot be linearly increased in size in proportion to increased loads). The structural stability of the pyramid, whilst primarily gained from its shape, relies also on the strength of the stone from which it

X-bracing - Misplaced Pages Continue

2310-884: The motion of any substance that can be experienced or perceived by humans without the help of instruments. In short, when mechanics concepts surpass being theoretical and are applied and executed, general mechanics becomes applied mechanics. It is this stark difference that makes applied mechanics an essential understanding for practical everyday life. It has numerous applications in a wide variety of fields and disciplines, including but not limited to structural engineering , astronomy , oceanography , meteorology , hydraulics , mechanical engineering , aerospace engineering , nanotechnology , structural design , earthquake engineering , fluid dynamics , planetary sciences , and other life sciences. Connecting research between numerous disciplines, applied mechanics plays an important role in both science and engineering . Pure mechanics describes

2365-508: The nanoscale, i.e., only the thickness of the surface of an object is between 0.1 and 100 nm. Nanotubes have two dimensions on the nanoscale, i.e., the diameter of the tube is between 0.1 and 100 nm; its length could be much greater. Finally, spherical nanoparticles have three dimensions on the nanoscale, i.e., the particle is between 0.1 and 100 nm in each spatial dimension. The terms nanoparticles and ultrafine particles (UFP) often are used synonymously although UFP can reach into

2420-411: The people responsible for maintaining a facility's medical equipment. Any structure is essentially made up of only a small number of different types of elements: Many of these elements can be classified according to form (straight, plane / curve) and dimensionality (one-dimensional / two-dimensional): Columns are elements that carry only axial force (compression) or both axial force and bending (which

2475-451: The professional structural engineers come into existence. The role of a structural engineer today involves a significant understanding of both static and dynamic loading and the structures that are available to resist them. The complexity of modern structures often requires a great deal of creativity from the engineer in order to ensure the structures support and resist the loads they are subjected to. A structural engineer will typically have

2530-443: The response of bodies (solids and fluids) or systems of bodies to external behavior of a body, in either a beginning state of rest or of motion, subjected to the action of forces. Applied mechanics bridges the gap between physical theory and its application to technology . Composed of two main categories, Applied Mechanics can be split into classical mechanics ; the study of the mechanics of macroscopic solids, and fluid mechanics ;

2585-470: The results of these inquiries have resulted in improved practices and a greater understanding of the science of structural engineering. Some such studies are the result of forensic engineering investigations where the original engineer seems to have done everything in accordance with the state of the profession and acceptable practice yet a failure still eventuated. A famous case of structural knowledge and practice being advanced in this manner can be found in

2640-407: The role of master builder. No theory of structures existed, and understanding of how structures stood up was extremely limited, and based almost entirely on empirical evidence of 'what had worked before' and intuition . Knowledge was retained by guilds and seldom supplanted by advances. Structures were repetitive, and increases in scale were incremental. No record exists of the first calculations of

2695-521: The strength of structural members or the behavior of structural material, but the profession of a structural engineer only really took shape with the Industrial Revolution and the re-invention of concrete (see History of Concrete ). The physical sciences underlying structural engineering began to be understood in the Renaissance and have since developed into computer-based applications pioneered in

2750-763: The study of electricity and magnetism . Engineering problems are generally tackled with applied mechanics through the application of theories of classical mechanics and fluid mechanics . Because applied mechanics can be applied in engineering disciplines like civil engineering , mechanical engineering , aerospace engineering , materials engineering, and biomedical engineering , it is sometimes referred to as engineering mechanics. Science and engineering are interconnected with respect to applied mechanics, as researches in science are linked to research processes in civil, mechanical, aerospace, materials and biomedical engineering disciplines. In civil engineering , applied mechanics’ concepts can be applied to structural design and

2805-420: The study of the mechanics of macroscopic fluids. Each branch of applied mechanics contains subcategories formed through their own subsections as well. Classical mechanics , divided into statics and dynamics , are even further subdivided, with statics' studies split into rigid bodies and rigid structures, and dynamics' studies split into kinematics and kinetics . Like classical mechanics , fluid mechanics

SECTION 50

#1732901188231

2860-729: The techniques of structural analysis , as well as some knowledge of the corrosion resistance of the materials and structures, especially when those structures are exposed to the external environment. Since the 1990s, specialist software has become available to aid in the design of structures, with the functionality to assist in the drawing, analyzing and designing of structures with maximum precision; examples include AutoCAD , StaadPro, ETABS , Prokon, Revit Structure, Inducta RCB, etc. Such software may also take into consideration environmental loads, such as earthquakes and winds. Structural engineers are responsible for engineering design and structural analysis. Entry-level structural engineers may design

2915-407: The weight of the amount of fluid that was displaced by said solid. Further developed upon by proposition 5, if the solid is lighter than the fluid it is placed in, the solid will have to be forcibly immersed to be fully covered by the liquid. The weight of the amount of displaced fluids will then be equal to the weight of the solid. This section based on the "AMR Subject Classification Scheme" from

2970-616: The world. Since this first meeting the congress has been held every four years, except during World War II ; the name of the meeting was changed to International Congress of Theoretical and Applied Mechanics in 1960. Due to the unpredictable political landscape in Europe after the First World War and upheaval of World War II many European scientist and engineers emigrated to the United States. Ukrainian engineer Stephan Timoshenko fled

3025-463: Was A Manual of Applied Mechanics in 1858 by English mechanical engineer William Rankine . August Föppl , a German mechanical engineer and professor, published Vorlesungen über technische Mechanik in 1898 in which he introduced calculus to the study of applied mechanics. Applied mechanics was established as a discipline separate from classical mechanics in the early 1920s with the publication of Journal of Applied Mathematics and Mechanics ,

#230769