Deflection (engineering)

About: Deflection (engineering) is a research topic. Over the lifetime, 30862 publications have been published within this topic receiving 298849 citations.

Tension Stiffening in Reinforced Concrete Slabs

Abstract: A nonlinear finite element model is used to predict the short-term behavior of reinforced concrete slabs under transverse service loads. The model is based on small deflection plate bending theory and uses a layered 16-degree-of-freedom rectangular plate bending element. The sources of material nonlinearity in reinforced concrete slabs are examined and accounted for in an incremental nonlinear solution procedure. Various methods are considered for treating the tension stiffening effect that occurs between the cracks in the tensile concrete in regions close to the reinforcement. Numerical calculations are used to assess the relative merits of these methods and to test the validity of the model. A simple treatment of the tension stiffening effect is proposed in which a modification is made to the tensile stress-strain diagram for the reinforcing steel. This produces accurate results with relatively economic use of computer time.

Papermaking belt having semicontinuous pattern and paper made thereon

Abstract: A secondary belt for papermaking. The belt has a framework of protuberances arranged in a semicontinuous pattern to provide a semicontinuous pattern of deflection conduits. The semicontinuous pattern is distinguished from the discrete and continuous patterns of the prior art. The protuberances may be generally parallel, or may provide individual cells within the deflection conduits between the protuberances. Also disclosed is the paper made on such a secondary belt.

Modeling and avoidance of static form errors in peripheral milling of plates

Abstract: Peripheral milling of very flexible, cantilevered plates with slender end mills is modeled. The plate has varying structural properties in the axial and feed directions due to metal removal. The cutter is modeled as a cantilevered continuous elastic beam with flexible clamping in the collet. The plate structural properties are updated using the finite element technique as the cutter and plate interact at changing contact zones along the feed direction. The analytical cutting force and surface generation model considers partial separation of tool and plate structures due to static displacements. The experimentally verified model predicts the cutting forces and dimensional surface error on the plate. The model identifies the required feed variation along the plate in order to keep the static form errors within the specified tolerance of the part. The model is developed to improve dimensional accuracy in peripheral milling of very flexible aerospace components.

Polycrystalline Silicon Micromechanical Beams

Abstract: Using the conventional MOS planar process, miniature cantilever and doubly supported mechanical beams are fabricated from polycrystalline silicon. Poly‐Si micromechanical beams having thicknesses of 230 nm to 2.3 μm and separated by 550 nm to 3.5μm from the substrate are made in a wide range of lengths and widths. Two static mechanical properties are investigated: the dependences of maximum free‐standing length and beam deflection on the thickness of the beam. By annealing the poly‐Si prior to beam formation, both of these properties are improved. Nonuniform internal stress in the poly‐Si is apparently responsible for the beam deflection.