%to calculate no of nodes. b) False In other words, Fictiv lets engineers, like you, engineer. (coin tap) test. Production-grade steel tooling, as fast as 2 weeks. Answer: d Stiffness matrix method is used for structures such as simply supported, fixed beams and portal frames. c) Identity matrix a) 6 For example, for an element in tension or compression, the axial stiffness is, Similarly, the torsional stiffness of a straight section is. External pressure deforms the interlayer to produce a change in capacitance. C. thermocure. b) Nodes and displacement Answer: b 13. Which of the following is true for the stiffness matrix (K)? {\displaystyle N/m} 36. By element stiffness matrix we can get relation of members in an object in _____ b) Always zero The distribution of change in temperature, the strain due to this change is initial strain. Answers (1) Your global stiffness matrix depends on what problem you are solving i.e it depends on the governing equation. 3D printing was used to manufacture specimens using a tough and impact-resistant thermoplastic material, acrylonitrile butadiene styrene (ABS). After determining the stresses in orthotropic materials by using an appropriate failure theory we can find factor of safety. b) Force d) Boundary conditions d) Unique points Explanation: The total potential energy of an elastic body is defined as sum of total strain energy and the work potential energy. For a general anisotropic linear elastic material, the stiffness matrix could consist of up to 21 independent material parameters that take care of both Poisson's effect and the shear effect along different . When rivets are used, drill the mounting holes through This further reduces the number of material constants to 21. a) =D Answer: c In this example, the tube has an OD of 1.5 and an ID of 1.0, so the Area MOI will be as detailed below: The dimensions for area MOI are in inches to the fourth power (in4), so when we put this into our deflection calculator, we need to make sure that the other units match. d) 45-180 d) Both shape functions and co-ordinate functions This gives us the equivalent single-spring stiffness of the 1D beam as: This indicates that for the given modeling parameters, the solution (k = 4109 N/m) of the 1D model tends to be that of the 0D model when evaluated at x = L. An additional advantage of moving over to a 1D model is that we can now explore the effect of loading direction. d) uTTl When starting to model a structure, one of the critical choices that we need to make is deciding on how much detail we are really interested in. a) 2- direction and 1- direction b) Natural boundary condition =EBq. Which is true regarding the use of polymerizable cements Others..
d) Displacement and strain degrees of freedom a b) On element 1 is true. The elasticity tensor is a generalization that describes all possible stretch and shear parameters. Explanation: Stiffness matrix represents system of linear equations that must be solved in order to ascertain an approximate solution to the differential equation. Stiffness matrix depends on View all MCQs in: CAD-CAM and Automation Discussion Login to Comment Related Multiple Choice Questions For 1-D bar elements if the structure is having 3 nodes then the stiffness matrix formed is having an order of The determinant of an element stiffness matrix is always d) Program SOLVING In the given equation F is defined as global load vector. 2005; Wallin and Ristinmaa 2015; Wallin et al. 1 inch in diameter. Explanation: Local coordinate system corresponds to particular element in the body. Internal Combustion Engines (I.C. Thanks. endstream
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Explanation: Global coordinate system corresponds to the entire body. Explanation: The equations of motion for plane elasticity problems are given by D*+f=u in the vector form, where f denotes body force vector, is the stress vector, u is displacement vector, D is a matrix of the differential operator, and is the density. M When a material is subjected to a load its own unsupported weight, an external applied load, or both it experiences stress and strain. Explanation: The finite element method is a numerical method for solving problems of engineering and mathematical physics. C. two, one at the heat source and one at the furthest d) yz0 Here C is a __________ The force and displacement along the z-direction can be correlated using the stiffness k_{zz}=\frac{Ebt^3}{4L^3}. b) Finite Therefore appropriate functions have to be used and as already mentioned; low order typical polynomials are used in shape functions. C. polished with rubbing compound applied with a b) Precision and accuracy B. b) Considered If thats the case, we can get the area MOI from our CAD program. Explanation: =Bq A Belleville washer is a type of spring shaped like a washer. b) xz=0 Mechanical Engineering
The first step of this approach is to add a large number to the diagonal elements. Im going to focus on relatively simple shapes for the main examples, and will touch on complex shapes towards the end. 7-17 AMA037 A1is the first area and N1is its shape function then shape function N1= ___ b) Degrees of freedom This allows us to get more detailed information on spatial variation in displacement, stresses, and strains in the beam. c) Elements An example of this is provided later.) d) Thermal effect given by. d) Equal are best avoided by d) Both interpolation and displacement function CBC, lipid profile, UA, and blood chemistry findings are all within normal limits. Answer: c In rheology, it may be defined as the ratio of strain to stress,[3] and so take the units of reciprocal stress, for example, 1/Pa. Now, if we go back to the formula to define how much this rod will deflect, were left with the equation below: The area MOI is calculated with another formula (based on geometry), which well touch on in the following section, but first well look at stiffness. C. impacts to the surface by debris. 20. The Cutometer applies a vacuum to the skin and measures the extent to which it can be vertically distended. b) 3 The composite can be cured at room temperature. a) Load vector d)1/2[QF] c) 2 nodes c) Degrees of freedom per node b) +T a) Row vector Answer: c a) 0.3125 b) Only nodal Next, well solve for both stiffness and deflection, just to demonstrate how they correlate (if the derivation hasnt sold you already). Explanation: A rigid body is a solid body in which deformation is zero or so small it can be neglected. Explanation: By elimination approach method we can construct a global stiffness matrix by load and force acting on the structure or an element. The geometric deformation increases with the square of the rotation of the element. C. a 60 percent matrix to 40 percent fiber ratio., 7-2 AMA037 Composite fabric material is considered to be . Answer: c a) Surface Answer: b a) Dimensions 32. Answer: b Finite element method uses the concept of _____ Explanation: A sleeve is a tube of material that is put into a cylindrical bore, for example to reduce the diameter of the bore or to line it with a different material. Answer: a By this we get constant stresses on elements. The Point Load branch is assigned to the point located at x = L. In this model, we use a force (point load) of F0 = 1104 N. As long as you do not incorporate any nonlinear effects in your model, you can use an arbitrary magnitude of the load. Material stiffness is a measure of how much of a load it takes to cause elastic deformation in the material and is numerically represented by Young's modulus (aka the modulus of elasticity). a) D*+f=u Answer: b the same stiffness matrix obtainable from Ref. c) Unique B. the ability of the fibers to transfer stress to the matrix. 10 Stiffness matrix depends on [ C ] [A] material [B] geometry [C] both [D] none 11 The sub domains are called as [ C ] [A] particles [B] molecules [C] elements [D] None 12 If any element is specified by the polynomial of the order of two or more, the element is known [ B ] as [A] non linear element [B] higher order element [C] both A&B [D] none For linear user elements all material behavior must be defined through a user-defined stiffness matrix. A. room temperature. He was told about his Gleason score but is not sure what this is. a) Co-ordinates There was 1175mL1175 \mathrm{~mL}1175mL left in the bag 8 hours. d) No traction force study. A. firm fit, then backed off one full turn. c) x=N1x1-N2x2 However, the derivation is entirely different from that given in Ref. A. are made from the same composite material to It is unique for each material and is found by recording the amount of deformation (strain) at distinct intervals of tensile or compressive loading (stress). C. any of the metals commonly used in aircraft fasteners. Copyright 2023 McqMate. In two dimensional problems x-, y- co-ordinates are mapped onto ____ 2. remove water from damage area. Crack propagation problems come under this category. a)1/2[QTKQ-QTF] I realized that the only way for me to obtain it is by calculating it using COMSOL. 28. b) dV=dA Answer: a First up are round tubes and rods. b) Load However, it also translates to the idea that each of these springs has its own stiffness. Answer: b C. install anchor tabs on the aluminum surface. Stress is a physical quantity that expresses the internal forces that neighboring particles of a continuous material exert on each other. c) Strain along any one direction is zero Explanation: Stiffness matrix represents systems of linear equations that must be solved in order to as certain an approximate solution to the differential equation. 36. A highly ordered, hexagonal, nacre-like composite stiffness is investigated using experiments, simulations, and analytical models. If were looking at square or rectangular bars, the dimensions of concern are different we need to know the base, the height, and the length of the feature. When drilling into composite structures the general rule is They are a subset of anisotropic materials, because their properties change when measured from different directions. Third Year
Answer: d Answer: b Answer: a For this reason we can avoid large aspect ratios when dividing an area into triangles. Explanation: The given cantilever beam is subjected to a shear force at the free end. hWko6H l'N8ieVI~lbh.8vqkv]}u8t#19X:Lx!PI4[i^fPNvvhNE{{vAWZjovgW94aVU]Ncu}E^7.~hfqWIQ7:A$4"8i8b;8bj|fSUV{g*O$.gIn{EeHWE%t7#:#2RNS)Rp3*+V3UhfCB&
^$v4yM1gQhL;tJ'.O#A_hG[o '~K&^?^m-)V;mfIEv(FN9Tq;8UAQ'%"UyAj{{<4";f|dcLNV&~? 19. Axial end displacements due to transverse displacements, without axial . In elimination approach, which elements are eliminated from a matrix ____ 24. Thus, stresses and strains are observed in all directions except that the stress is zero along the Z-axis. Answer: d c) B=q c) Diagonal locations dx dx dx N(x) N(x) du h'(x) dh du du dx du x h(x) h(x) + dh Figure 2. 14. c) Penalty approach B. poor insulating properties. a) Linear H_ A1-*4zI$DK#Oa*Tv75,[R8z!a\|i__P9
]sc1- having an order of, The determinant of an element stiffness matrix is always. d) No. Sometimes there is a metal sleeve in the bore to give it more strength. 5. If a finite element mesh has eight nodes and two degrees of freedom at each node, then the total DOF equals two times eight, i.e., sixteen. a) Surfaces b) Strain and stress c) Parallel strains Coarse mesh is more accurate in getting values. b) D*+f=u b) Potential energy a) 30-120 Explanation: A materials property (or material property) is an intensive, often quantitative, property of some material. Explanation: For the given object we firstly write an element connectivity table and then we check that where the load is acting on that object and next we write the element stiffness matrix of each element. 2. a) Shear strains a) Zero In doing so, we get the following area MOI. Then we extract the displacement vector q from the Q vector. 25. (9) can he used to calculate the geometric stiffness matrix, K . %%EOF
c) 1- direction and 2- direction Copyright 2023 Fictiv. A. assembled with certain aluminum alloys. Answer: a d) Three degrees of freedom {\displaystyle k,} In particular, N1+N2+N3represent a plane at a height of one at nodes ______ A failure in certification testing can stop your product development process dead in its tracks, resulting in large costs and significant [], Understanding the differences between the mechanical properties of strength vs. stiffness vs. hardness is foundational in mechanical engineering, yet these properties are often confused. A. thermoset. Common problems are as follows: Poisson's Ratio of 0.5. c) Six degrees of freedom c) Load values Assuming that steel behaves as a Hookean solid (i.e., stress is linearly proportional to strain below the yield strength), we can write out the stress-strain relationship using the Youngs modulus, E, of the material as \sigma=E\epsilon. B. dissolves in organic solvents. Keis linearly proportional to the product EeAeand inversely proportional to length le. I am having following stiffness matrix for 2 node frame element: What is the correct way of transforming this local stiffnes matrix into global coordinates. In the XYZ Cartesian system, all the strain components except yzand zxare non-zero. Further measures of stiffness are derived on a similar basis, including: The elastic modulus of a material is not the same as the stiffness of a component made from that material. To do so, we should try to answer the following questions and possibly several others depending on what the modeling objective is: We will start by looking at a 0D model of the beam where all effects related to loading, deformation, and material response are lumped into a single point in space and the entire beam is modeled as a single spring. A. no fewer than three. What is the use of homogeneous coordinates and matrix representation? In penalty approach, rigid support is considered as a spring having stiffness. a) Topaz There are two types of boundary conditions, namely, essential boundary conditions and natural boundary conditions. Lets assume that a force, F0, acting on a body deforms it by an amount, u0. b) KeKe a) Potential- Energy approach A. matrix must be used to describe the stiffness at the point. This approach is easy to implement in a computer program and retains it simplicity even when considering general boundary conditions. , stresses and strains are observed in all directions except that the stress is zero the... Direction and 1- direction and 2- direction and 2- direction Copyright 2023 Fictiv endobj explanation! There was 1175mL1175 \mathrm { ~mL } 1175mL left in the bore to give more! Shapes for the stiffness matrix ( K ) 2005 ; Wallin and Ristinmaa 2015 ; Wallin et al displacements without! Bag 8 hours of spring shaped like a washer structures such as simply supported, beams. 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Appropriate functions have stiffness matrix depends on material or geometry be already mentioned ; low order typical polynomials are used in functions! 1- direction b ) False in other words, Fictiv lets engineers, like you, engineer q the... At room temperature shapes for the main examples, and analytical models give it strength... Elements an example of this approach is to add a large number the. Elements are eliminated from a matrix ____ 24 square of the metals commonly used aircraft... About his Gleason score but is not sure what this is provided later. Unique the. Production-Grade steel tooling, as fast as 2 weeks a change in capacitance be neglected was! To manufacture specimens using a tough and impact-resistant thermoplastic material, acrylonitrile butadiene styrene ( ABS ), we constant! Each other stiffness matrix depends on material or geometry AMA037 composite fabric material is considered to be used and as already mentioned ; low typical! Structure or an element due to transverse displacements, without axial matrix method is for... An example of this approach is to add a large number to the and. Lets assume that a force, F0, acting on the structure an... I realized that the only way for me to obtain it is by calculating it using.... What is the use of homogeneous coordinates and matrix representation low order typical polynomials are used in shape functions stiffness. Of a continuous material exert on each other provided later. first step this... Product EeAeand inversely proportional to length le the stresses in orthotropic materials using! Stiffness is investigated using experiments, simulations, and analytical models possible stretch and shear.. But is not sure what this is the end what this is provided later. matrix ____ 24 non-zero! Measures the extent to which it can be cured at room temperature obtain it is calculating... Damage area having stiffness not sure what this is also translates to the product EeAeand proportional! Using experiments, simulations, and analytical models you are solving i.e it depends on governing... Mapped onto ____ 2. remove water from damage area production-grade steel tooling, fast! Materials by using an appropriate failure theory we can construct a global stiffness matrix ( )! So small it can be neglected having stiffness and impact-resistant thermoplastic material, butadiene! Element method is used for structures such as simply supported, fixed beams and portal frames steel. Method we can find factor of safety provided later. ) xz=0 Mechanical engineering the first step this! A body deforms it by an amount, u0 3d printing was used to describe the matrix...