Showing papers on "Flexural rigidity published in 1984"

9—fabric stiffness, handle, and flexion

Abstract: The stiffness of some woven and non-woven fabrics is assessed subjectively and measured objectively. Magnitude estimations of stiffness by hand are found to correlate with values of flexural rigidity obtained by bending-hysteresis measurements on a Shirley Cyclic Tester. Comparisons are made of fabric properties, such as mass, thickness, density, and volume. Objective measurements of fabric stiffness by Shirley Cantilever, Cusick Drapemeter, and Shirley Cyclic Tester methods are also compared.

Bending Rigidity and Hysteresis of Wool Worsted Yarn

Abstract: The bending rigidity of wool worsted yams was estimated from the mean fiber diameter together with four correction factors due to fiber diameter distribution, yam twist, fiber ellipticity, and mean...

Complex Triaxial Fabrics—Cover, Flexural Rigidity, and Tear Strength:

Abstract: The properties of complex triaxial fabrics are examined and compared to earlier results presented for the simplest case of the triaxial weave. Cover factor results for the case of the basic weave are extended to the general triaxial case, which admits the stacking of three yarns. The tear strength (tongue) of complex triaxial fabrics is shown to be independent of the orientation of the test, altfiough the mode of tear propagation differs. Flexural rigidity is shown to vary with orientation angle, indicating that unlike simple triaxial fabrics, the effect of interlacing cannot be ignored.

Co-oscillating, volume-changing resonator in the form of a silencer

Abstract: A co-oscillating, volume-changing resonator in the form of a silencer, includes a lens-shaped housing formed of a material having a given flexural stiffness, the housing being arched defining an evacuated cup-shaped cavity formed therein, and a coating layer completely surrounding the housing, the coating layer being formed of a material having a flexural stiffness being at most one-third of the given flexural stiffness of the material of the housing.

Theoretical Calculation of the Bending Rigidity of Fused Fabric Composite

Abstract: This paper aims to predict the bending rigidity of the fused fabric composite composed of a face fabric and fusible interlinings. A simple model of the fabric composite is proposed in order to predict the bending rigidity of such a fabric system. The results are summarized as follows :(1) The bending rigidity of the fabric composite is theoretically derived from bending rigidities of the face and interlining fabrics, thicknesses of the face and interlining fabric and the size of the adhesive spots and the spot density.(2) Nine interlining fabrics having different densities of adhesive resin spot were fused to the one face fabric resulting in nine different fabric composites being tested. The accuracy of the theoretical calculation was examined experimentally by using the KES-FB2 Pure Bending Tester, and good agreement between theoretical and experimental results was obtained by using this simple structural model.

Reinforcing construction for transverse girder structural member in sliding door type vehicle

Abstract: PURPOSE:To enhance flexural rigidity of a transverse girder structural member by a simple construction, by connecting a sheet part to the back side of a striker-fixing part of a shelf part CONSTITUTION:An entering part at the tip of a guide rail 4 is provided with sufficient flexural rigidity by the presence of a reinforcement 5 Also at the fixing part for a striker 9, facial rigidity of the part can be enhanced by connecting the sheet part 5C to the shelf part 2a In addition, since the sheet part 5C is integral with an extended part 5A of the reinforcement 5 and is contiguous with the reinforcement 5 on the entering part side of the guide rail 4 through a bridge part 5B, flexural rigidity of this part can be enhanced

Material design of fibrous laminated composites with required flexural stiffness

Abstract: A new material design method of fibrous laminated composites with required flexural stiffness is proposed. The selection of kinds of fibers and matrices and the determination of fiber orientation angles can be done directly from the imposed conditions on the flexural stiffness of laminated plates.

Investigation of the flexural and torsional rigidity of flexible elements of endoscopes

Abstract: 1. Methods and a device were developed for determining both under laboratory and production conditions the flexural and torsional rigidity of flexible endoscope elements. The documentation on the indicated methods and device were supplied to industry. 2. The flexural rigidity of the uncontrollable working part of the Olympus (Japan) medical endoscopes is two-stage. In the distal part on a section up to 0.36–0.4 m it has a value of 7.3 kgf/cm2 for single-channel colonofibroscopes and 10 kgf/cm2 for two-channel colonofibroscopes and on the remaining section (closer to the control casing) it is 50% greater. 3. The flexural rigidity of the uncontrollable working part on a section 0.1–0.2 m from the distal end for ACM (USA) single-channel colonoscopes is 1.3 times greater than for the Olympus (Japan) ones. In the section greater than 0.2 m the flexural rigidity of the ACM colonoscopes is multistage (it has five sections with a different rigidity) and in different sections has values 1.3–3.7 times greater than that of the Olympus colonofibroscopes. 4. The flexural rigidity of the uncontrollable working part of the ACM two-channel colonoscopes is 2.8–2.4 times greater than in the Olympus colonofibroscopes. 5. The outer polyurethane coating made by the extrusion method on stainless steel braiding bears the greater part of the torsional rigidity (62%) of the uncontrollable working part of the Olympus colonoscopes. 6. The results of investigating the flexural and torsional rigidity of the working part of flexible foreign endoscopes made it possible to give recommendations on the design and improvement of the working part of Soviet flexible endoscopes.

Coupling Action of Slabs in Hull‐Core Structures

Abstract: The coupling action of a slab which is connected by moment‐resisting joints to the core and peripheral frames in a laterally loaded hull‐core structure is investigated by a finite element method. The relative influences of a range of geometrical and stiffness parameters are evaluated. It is found that the column to slab flexural stiffness ratio has a significant effect on the rotational stiffness and effective width of the slab, but practical variations in column axial stiffnesses have negligible effects on the slab stiffness. With a constant column‐slab flexural stiffness ratio, the influences of both column spacing and spandrel beam stiffness are negligible. The effective slab width increases with both relative core width and core depth. Curves are presented to facilitate the evaluation of rotational stiffness and effective width for practical situations. The coupling action reduces the shear lag in the outer framed‐tube.

Slope protection work

Abstract: PURPOSE:To stabilize sloped ground by a method in which expand metal frames having a high flexural rigidity and a trench-shaped cross section are set on the slope to prevent the degradation of the ground and also to form concrete formworks CONSTITUTION:An expand metal having a high flexural rigidity is processed into a trench form to obtain a straight frame 1a and a crossed frame 1b The upper stage portion of the sloped ground is cut off for grading the ground, and the frames 1 are set in a latticed form by touching their bottoms with the slope The frames 1 are fixed to rocked 5 by rock anchors 2, and the surface layer of the slope is compacted and fixed between the rockbed 5 and the frames 1 by clamping the anchors 2 Cement mortar or concrete is placed on the whole surface of the slope and slope frames are formed in the frames 1 portion Tensed and fixed slope frames can thus be formed by the rock anchors 2

Equilibrium of a tip weighted curved sheet on an inclined plane

Abstract: One end of a long, naturally curved elastic sheet is clamped onto an inclined plane. The other end is acted on by a constant vertical force which tends to open the curved sheet. This nonlinear large deflection problem is studied by series perturbation, numerical integration and exact analytic solution. The occurrence of roll-up depends on the angle of the inclined plane an a nondimensional parameter representing the importance of curvature and flexural rigidity to that of the end load.

Wave-Forced Vibration of Floating Compliant Platforms

Abstract: The essential feature of this study is harmonic resonance of floating compliant structures which are elastically vibrating in regular waves.The conceps of “characteristic bending moment” which is determined with no consideration about structural elasticity is introduced. It is proved to be efficient in estimating significant wave length condition (L/λ) for various vibration mode shape on which significant bending moment response appears.The bending moment response is amplified by flexural vibration. The amplification factor of resonant bending moment is dependent primarily on the effectiveness factor of the flexural rigidity of the structure which is defined as EI (mj/L4)/k.Consequently, the amplitude of harmonically resonant bending moment is found to be estimated through the characteristic bending moment and the amplification factor.Significant third harmonic resonance which is induced by non-linear wave force was observed in the experiment. Super-harmonic resonance in bending moment response is investigated through numerical calculation using higher order term of drag force which is expressed in Morison's equation.

Stress concentration factors for welded tubular t-joints using finite element analysis with automatic mesh generation

Abstract: The paper presents the finite element analysis for stress concentration factors of welded tubular T-joint. The development of a computer software for discretising the joint using automatic mesh generation technique is discussed together with an interactive graphics. The shell analysis includes the membrane stiffness representation by the plane stress element and the flexural stiffness by the plate bending element. The stress concentration factors are obtained which show good agreement with the experimental results published in literature and the values based on parametric equiations.

Lightweight transport support plates for workpieces

Abstract: Workpieces (7) are clamped to a relatively thin support plate (6) which consequently has low flexural rigidity. To ensure accurate positioning of the workpiece (7) the support plate is clamped to a heavier and rigid table (5). The support plate and workpiece are then removed from the rigid table (5) and delivered to a store (3) and subsequently to the work station (1). At the workstation the support plate is again clamped to a rigid table (5) which is identical to the one used at the clamping station(4). Both tables (5) are provided with means to clamp the support plate at a large number of points to ensure its accurate alignment.

Thermal deformation absorbing flexible piping

Abstract: PURPOSE:To detect occurrence of cracks by a method wherein rigidity at the cracked part is obtained from the ratio of a variation in displacement of the cracked part to a variation in the average temperature of main pipings at that time, and a change in the rigidity is utilized for detection. CONSTITUTION:When a breeder or the like is started up, a liquid Na in a main container 1 is gradually raised up in its temperature to heat the entire of a piping 3 slowly while keeping substantially uniform temperature therethrough, as the liquid advances toward an intermediate heat exchanger 2. During this process, a flexible pipe 6 is deformed to bend in proportion to an amount of thermal expansion of main pipings 4, 4, and the corresponding displacement is detected at a displacement terminal 8 locating at the flank of the flexible pipe 6 as well as at a displacement terminal 9 locating on the back of the welded end between the flexible pipe 6 and the main piping 4. In case of the presence of any crack, when the stress at the cracked part comes under the tensioned side after the initial change in temperature, a change in displacement is increased due to widening of the crack, thus resulting in a reduction of bending rigidity. Accordingly, by dividing a range between the temperature at start-up and the temperature during the normal operation into 10 zones equal to each other and then measuring a variation in displacement for each temperature zone, it becomes possible to clearly detect the presence of crack because the measured variation will exhibit a larger reading in higher temperature zones.

Determination of the flexural stiffness of carbon composite plates by holographic interferometry

Abstract: A method of measuring the flexural stiffness properties of anisotropic thin plates is presented Three rhombic plates cut at different orientations from the test sheet are loaded in bi-axial bending, and the resulting deflections are recorded as fringe patterns using optical holography Curvatures determined in the chosen coordinate system and related to the bending moments are used to calculate the flexural stiffness terms The results of tests on cross-ply carbon fibre reinforced plastic material are in good agreement with laminated plate theory

Radial tire improved durability in running on bad road

Abstract: PURPOSE:To improve durability of a radial tire, by providing a cord, whose bending rigidity at the outermost layer of a belt made of cord cloth coated with rubber of at least double layers is low as compared with the remaining layer, in arrangement whose driving-in density is far high. CONSTITUTION:A belt made of cord cloth coated with rubber of at least double layers obtained by making it into a laminated layer wherein the cords are crossed with each other and a carcass made of the cord cloth coated with at least a layer of rubber which becomes in a cord arrangement meeting at right angles with an equatorial surface actually are made into reinforcement of a body, in the cord arrangement inclining at a comparatively small angle to the equatorial surface. The cord whose bending rigidity at the outermost layer of the belt is low as compared with the remaining layer, is provided in arrangement whose driving-in density is far high. With this arrangement, the durability of a radial tire in running on a bad road is improved.

Watersport device with a longitudinally extended boat hull

Abstract: A watersport device with a longitudinally extended boat hull, consisting of an upper shell and a lower shell connected thereto and made of plastics material, in which the hollow void between upper and lower shell is foam-filled by a foamable plastic, and the upper and the lower shell are designed with different flexural stiffness to increase the damping effect to dynamic flexural loads. The different flexural stiffness can be achieved with different material thicknesses, materials with different specific flexural stiffnesses or a combination of the two measures.