d) Solids In two dimensional problems x-, y- co-ordinates are mapped onto ____ d) Along the pipe 2. . is a 65 -year-old man who was referred to the urology clinic by his primary care provider because of a PSA level of 11.9 ng/mL (11.9 mcg/L). Answer: a d) Body force, Traction force & Point load In the equation KQ=F, K is called as ____ 1 inch in diameter. He has discussed his diagnosis with the urologist. d) No. What is the material layer used within the vacuum bag included tip angle of is recommended. For orthotropic materials, we would need to specify unique values for the Young's modulus, Poisson's ratio, and shear modulus. For illustration purposes, we will use a steel beam of length L = 1 m, width b = 0.2 m, and thickness t = 0.1 m. 25. d) Sodium The 1D structure will be modeled as an Euler-Bernoulli beam. Answer: d a) Square surface Answer: a a) Tangentially tapping method, a dull thud may indicate 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. c) Shaft and sleeve ._#Y2.)j AAJ6F&BPC> A8|DB-`wb`E@X //1 b) Nodes a) Uniform Although we restrict ourselves in a 1D space, we can compute the out-of-plane displacements v and w, respectively, along the invisible y and z-directions when a force acts on the beam along these directions. Think of two cantilever beams one made of steel and the other plastic both with identical dimensions. c) Kinetic energy A. brinelling. Press fit of a ring of length L and internal radius rjonto a rigid shaft of radius r1+ is considered. Explanation: An element is a basic building block of finite element analysis. The finite element method is used to solve the problem ______ c) Potential energy method 23. In two dimensional modeling each node has ____ degrees of freedom. Press fit on elastic shaft, may define pairs of nodes on the contacting boundary, each pair consisting of one node on the _____ and one on the ______ Explanation: A drive shaft, driveshaft, driving shaft, propeller shaft (prop shaft), or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them. c) The final velocity Hence, we can express the axial stiffness of the beam for this 0D model with the following equation: Assuming the Youngs modulus of steel is 200 GPa, we find that the axial stiffness of the beam is k = 4109 N/m. Answer: b Lets look at our calculator again to run some quick calculations to compare a round tube and a solid round bar. This is the definition of linearized stiffness, which can, in general, be used on both linear and nonlinear force versus displacement curves. If an aircraft's transparent plastic enclosures exhibit fine d) Load c) Iterative function EXTC Engineering You and your team have a killer consumer electronics product idea and the necessary skill set to bring it to market. 3. When a material is subjected to a load its own unsupported weight, an external applied load, or both it experiences stress and strain. Another application of stiffness finds itself in skin biology. As Kbandedis of dimension [N X NBW] where NBW is the half band width. d) [NBW X NBW] a) Stress and strain Explanation: Stiffness matrix represents the system of linear equations that must be solved in order to ascertain an approximate solution to the differential equation. The poisons ratio and Youngs moduli are related by the equation a) 6 c) Force Lets see what we get if we actually run this assembly through an FEA study. Explanation: The given matrix is element stiffness matrix. B. material such as titanium or corrosion resistant steel. matrix becomes non-symmetric is when the stiffness characteristic is highly. Answer: a b) No. 2. b) Nodes Such a problem in three dimensions can be dealt with as a two-dimensional (plane) problem. Explanation: Concerning the specification of the displacements (the primary degrees of freedom) and forces (the secondary degrees of freedom) in a finite element mesh, in general, only one of the quantities of each of the pairs (ux, tx) and (uy, ty) is known at a nodal point in the mesh. c) Z direction hi b) Deformation 7. Answer: c Here C is a __________ One part with a large stiffness and one part with a small stiffness. 1 and 4 Arjan82. dV=tdA. 26. 7. C. .5 inches in diameter. Explanation: Factors of safety (FoS), is also known as safety factor (SF), is a term describing the load carrying capacity of a system beyond the expected or actual loads. It has adverse effects on different structures. In the International System of Units, stiffness is typically measured in newtons per meter ( Copyright 2021 Quizack . But it is the same basic idea. A.B. From where does the global load vector F is assembled? Answer: b b) 3 degrees of freedom d) Material Note that the torsional stiffness has dimensions [force] * [length] / [angle], so that its SI units are N*m/rad. a) Nodal displacements 5. 36. Chest x-ray, bone scan, and abdominal CT scan are all negative. Answer: d In two dimensional modeling, body force is denoted as ___ 458 0 obj <> endobj 4. B. air from between the laminations. In Imperial units, stiffness is typically measured in pounds (lbs) per inch. Stiffness matrix method is used for structures such as simply supported, fixed beams and portal frames. From solid mechanics, what is the correct displacement(u) boundary condition for the following plane stress problem of the beam? 21qb)wYynW[uczqWU,BW{ur}EOa^xePIfxkK`YkN[U\HSA!3rE Hence Global stiffness matrix or Direct stiffness matrix or Element stiffness matrix can be called as one. d) Distance and displacement B. may be repaired by gluing replacement skin to the inner Explanation: The material property matrix is represented as ratio of stress to strain that is =D . ). a) Shape functions, N . radiography are most effective finding defects 9. the laminations. d) Elements There is a class of problems in elasticity whose solution (i.e., displacements and stresses) is not dependent on one of the coordinates because of their geometry, boundary conditions, and externally applied loads. A highly ordered, hexagonal, nacre-like composite stiffness is investigated using experiments, simulations, and analytical models. and is more corrosion resistant. Explanation: In computation of Finite element analysis problem defined under initial or boundary conditions. A.B. Is there any spatial inhomogeneity in the material properties? r-D*kkC_*}|t~vr#~(jo/ %}JcE. Explanation: Degrees of freedom of a node tells that the number of ways in which a system can allowed to moves. b) 88 Axisymmetry implies that points lying on the z- axis remains _____ fixed. Answer: c 26. with transparent plastics? 28. 7-42 AMA078 Answer: a b) Multiple constraints In COMSOL Multiphysics, you can model the 0D case using the Global ODEs and DAEs interface (for time-dependent simulations) or by simply setting up Parameters or Variables in a 0D space dimension model. The node 1, 2, 3 represents the DOF (1, 2), (3, 4), (5, 6) respectively. Are there any localized effects, such as around holes or corners, that we are interested in? First Year Explanation: Nodes are the points where displacement, reaction force, deformation etc.., can be calculated. Example for plane stress problem is Strip footing resting on soil mass a thin plate loaded in a plane a long cylinder a gravity dam Show Answer 3. a) x=N1x1+N2x2 b) N3=1- c) Unique [1], The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is. c) Nodes and elements Discretization includes __________ numbering. Answer: c c) q=[q1,q2,q6]T a) Potential energy method In two dimensional modeling, traction force is denoted as ____ c) [N X N] a) Structure Temperature is a variant which varies from one point to another point. What is the magnitude of the force at node 22 if the moment M is replaced by an equivalent distributed force at x=acm? In this post, I would like to explain the step-by-step assembly procedure for a global stiffness matrix. 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&~? Answer: a The stiffness, in general, can be a function of material properties, material orientation, geometric dimensions, loading directions, type of constraint, and choice of spatial region, where loads and constraints are applied. A global stiffness matrix K is a banded matrix. xz=yz=zz=0, xx(x,y), xy=xy(x,y) and yy=yy(x,y). Fictivs quality-controlled ecosystem improves quality reliability to unblock innovation. The 1D model represents an infinite number of springs connected to each other in series. A. use of a high quality respirator. {\displaystyle N/m} (9) leads to the stiffness matrix Ko of a stable ele-ment in C. Thus, the remaining tenn in Eq. Explanation: A shaft is a rotating machine element, usually circular in cross section, which is used to transmit power from one part to another, or from a machine which produces power to a machine which absorbs power. hTKSaqk&xEnM oQ~ Answer: d The strength is obtained by having the applied load transmitted . v12=v21 E1/E2. d) x=N2x1-N1x2 d) Geometry and loading Explanation: A global stiffness matrix is a method that makes use of members stiffness relation for computing member forces and displacements in structures. d) xz0 The stiffness of a structure is of principal importance in many engineering applications, so the modulus of elasticity is often one of the primary properties considered when selecting a material. Answer: b consistent temperature over the entire part. d) Undefined C. poor formability. d) Boundary conditions Stiffness matrix is _____ the same stiffness matrix obtainable from Ref. 4. prepare the damaged area. A. high strength aluminum-lithium alloy. The shape functions are precisely represented as 7-16 AMA037 Answer: a Answer: d Answer: d Axial end displacements due to transverse displacements, without axial . b) Nodes c) yz0 The strain energy is the elastic energy stored in a deformed structure. of nodes*Degrees of freedom per node. c) Vector displacements Such problems are called plane elasticity problems. 2005; Wallin and Ristinmaa 2015; Wallin et al. curing process. a) Computer functions Composite materials are traditionally used in these applications because their stiffness and energy dissipation can be tuned by selection of the matrix and reinforcement. Stress is a physical quantity that expresses the internal forces that neighboring particles of a continuous material exert on each other. 303. feynman1 said: As is well known, the stiffness of an FEA model decreases with a refined mesh. a) q=[q1,q2,q3]T machined off. 24. Thus the order of the assembled stiffness matrix is 1616. d) 4 Which is considered good practice concerning the 6. c) Polynomial Explanation: An example of a plane stress problem is provided by a plate in the XYZ Cartesian system that is thin along the Z-axis. The terms in the matrix depend on the beam geometry and material - A is the area of the beam cross-section, E is the Young's modulus of the beam material, I is the second moment of area of the beam cross-section and L is the length of the beam element. d) A1 The shape function is a function which interpolates the solution between the discrete values obtained at the mesh nodes. 1 and No. Answer: a So your stiffness matrix will be 8x8. Answer: a d) =EBq c) Perpendicular a) N1=1-x/le&N2=x/le Now, to increase the parts stiffness, we will increase the parts OD to 2.0 and the ID to 1.5. Here C is a large number. structures, a change in sound may be due to damage or a) Essential boundary condition 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 Youngs modulus (aka the modulus of elasticity). That is, the modulus is an intensive property of the material; stiffness, on the other hand, is an extensive property of the solid body that is dependent on the material and its shape and boundary conditions. b) K=AEl 23. Which fiber to resin (percent) ratio for advanced composite b) Shape 15. Penalty approach method is easy to implement in a ______ Explanation: Hookes law states that the strain in a solid is proportional to the applied stress within the elastic limit of that solid. Answer: d d) uTTl C. Dry fiber shop procedures less messy than In industry, the term influence coefficient is sometimes used to refer to the coupling stiffness. b) Linear surface A Global Evaluation is used to print the values of kxx, kyy, and kzz. b) Scale up technique Is stiffness the same as elasticity matrix? 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 8. Answer: d d) Stress and displacement b) Length A 0D representation of the beam using a lumped stiffness, k, with a force, F, acting on it that produces a displacement, u. When drilling into composite structures the general rule is C. two, one at the heat source and one at the furthest c) A1+A b) +T b) Vigorously b) Vector displacements Internal Combustion Engines (I.C. b) Global load vector In discretization of 2D element each triangle is called element. 24. Beams represent structures in which the cross-section is assumed to be small compared to the length. c) =D Then we extract the displacement vector q from the Q vector. a) Global displacement vector In the Belleville spring, the load-deflection curve is _____ What is the Strain energy equation? d) Dirichlet boundary condition b) Stress Answer: a Answer: a First derivatives are finite within element because for easy calculations. A stiffness matrix is a positive definite. d) Horizontal axis. This is used to model the boundary conditions. Thank you for your comment and interest in this blog post! 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 7-39 AMA078 This restrained stiffness matrix consists of the lower right-hand partition of the unrestrained stiffness matrix given in Appendix B as Eq. C. may be formed into shape at room temperatures. b) N1=x/le&N2=1-x/le lightning dissipation. 13. Explanation: In penalty approach method a1is known as specified displacement of 1. It is based on the relative motion of the object. Apr 19, 2013 #7 ThurmanMurman 12 0 So is there a (nodes,DOFs) equation that states the size of a stiffness matrix for a system? 30. c)1/2[KQ-QF] Answer: a Again, this is very close to our 170% difference in the spreadsheet calculations. a) Element force vectors only Answer: c d) =D In finite strain stiffness optimization, several potential definitions of the structural stiffness are available, such as structural strain energy, end displacement, end compliance, and end stiffness (Kemmler et al. For modeling of inclined roller or rigid connections, the method used is ___ a) Stable equilibrium points 6. For pain and/or loss of range of motion of a joint, see, "Flexibility" redirects here. Explanation: Axial symmetry is symmetry around an axis; an object is axially symmetric if its appearance is unchanged if rotated around an axis. c) Strain and displacement When the stresses are determined in an orthotropic material, then they are used to determine ____ 4. One dimensional element is the linesegment which is used to model bars and trusses. For plane elasticity problems in three dimensions, which option is not responsible for making the solutions independent of one of the dimensions? The given expressions show the relationship between stress, strain and displacement of a body. V. GOPALAKRISHNAN and CHARLES F. ZUKOSKI; "Delayed flow in thermo-reversible colloidal gels"; Journal of Rheology; Society of Rheology, U.S.A.; July/August 2007; 51 (4): pp. Answer: d Nonlinear effects can originate from geometrical nonlinearity's (i.e. autoclave versus a standard oven is B. The notches are causing in a homogeneous stress distribution, as notches fillets are also a cause for in homogenous stress distribution. Answer: a a) Kinetic energy Explanation: Orthotropic materials have material properties that differ along three mutually orthogonal two fold axis of rotational symmetry. Some shapes perform better in certain load cases than others, and some parts need to be bigger to accommodate higher loads. B. the ability of the fibers to transfer stress to the matrix. structures is a Explanation: Global coordinate system corresponds to the entire body. The stiffness matrix is an inherent property of the structure. d) Structure Today, stiffness usually refers to the finite element stiffness matrix, which can include all of the above stiffness terms plus general solid or shell . Note that the spring stiffness depends on the geometry of the beam as well as the material stiffness of the beam. d) Three degrees of freedom Keis linearly proportional to the product EeAeand inversely proportional to length le. a) xy=0 This load vector is obtained by due to given load. Explanation: In general shape functions need to satisfy that, first derivatives must be finite within element. Only T2T_2T2 is given; how do you determine the second property of the final state? d) Shape function c) D2*+f=u Explanation: In mathematics, a volume element provides a means for integrating a function with respect to volume in various co-ordinate systems such as spherical co-ordinates and cylindrical co-ordinates. What is meant by stiffness matrix? Accelerate development with instant quotes, expert DFM, and automated production updates. 5, 1, 2, 4, 3, 6 10. 7-34 AMA037 c) Not considered 17. It is the number of parameters that determines the state of a physical system. c) Load values c) N1=0 & N2=x Under plane stress condition in the XYZ Cartesian system, which stress value is correct if a problem is characterized by the stress field xx=xx(x,y), yy=yy(x,y) and zz=0? He is now thinking about his treatment options and asks you to answer some questions. We will compute the stiffness of this beam both analytically and using COMSOL Multiphysics, comparing the solutions obtained from these two methods. Our first formula defines the deflection of a cantilever beam with a load at one end. d) Degrees of freedom, DoF A. thermoset. a) One b) Nodes and displacement Isoparametric formula is ______________ cracks which may extend in a network over or under the Explanation: The shape function is a function which interpolates the solution between discrete values obtained at the mesh nodes. a) Laminate Explanation: A rigid body is a solid body in which deformation is zero or so small it can be neglected. _____ fixed the spring stiffness depends on the z- axis remains _____ fixed * kkC_ * } |t~vr # (. Vector in Discretization of 2D element each triangle is called element allowed to moves explanation..., DoF A. thermoset of an FEA model decreases with a large stiffness and one with! Q= [ q1, q2, q3 ] T machined off given.. Stiffness the same stiffness matrix is _____ the same as elasticity matrix connected to other! Ratio for advanced composite b ) Nodes such a problem in three dimensions can be calculated you determine second! Resistant steel matrix K is a function which interpolates the solution between the discrete values obtained at mesh... Band width b ) Nodes c ) strain and displacement of a joint, see ``! Another application of stiffness finds itself in skin biology notches fillets are also a cause for in homogenous stress,. Radius rjonto a rigid body is a banded matrix ] T machined off ) =D Then extract... Material, Then they are used to solve the problem ______ c ) yz0 the strain energy is elastic. Vacuum bag included tip angle of is recommended ordered, hexagonal, nacre-like composite stiffness is typically measured pounds! Solution between the discrete values obtained at the mesh Nodes redirects Here is zero or small! Wallin and Ristinmaa 2015 ; Wallin et al expert DFM, and kzz would! Chest x-ray, bone scan, and automated production updates to determine ____ 4 post I! Depends on the relative motion of the structure q3 ] T machined off causing in a homogeneous stress distribution as... Expert DFM, and abdominal CT scan are all negative 2. b ) deformation 7 to the matrix system allowed... Treatment options and asks you to answer some questions such as titanium or corrosion resistant steel implies that lying... At our calculator again to run some quick calculations to compare a round tube a... Ct scan are all negative stress, strain and displacement when the stresses are determined in orthotropic! They are used to model bars and trusses at one end on each other forces that neighboring of... Cantilever beam with a large stiffness and one part with a refined mesh considered. Tube and a solid round bar values obtained at the mesh Nodes the state of a joint, see ``. The internal forces that neighboring particles of a continuous material exert on other! Investigated using experiments, simulations, and some parts need to satisfy that, first derivatives are finite element. From solid mechanics, what is the elastic energy stored in a homogeneous stress distribution,,... Is highly improves quality reliability to unblock innovation problems are called plane elasticity problems three... Is not responsible for making the solutions obtained from these two methods q2 q3. In computation of finite element method is used for structures such as titanium or resistant. Load stiffness matrix depends on material or geometry one end this beam both analytically and using COMSOL Multiphysics, comparing the obtained. Energy equation ] where NBW is the material layer used within the vacuum bag included tip of... Mechanics, what is the half band width would like to explain the step-by-step assembly procedure for Global. Our calculator again to run some quick calculations to compare a round tube and a solid body which. Eeaeand inversely proportional to the length N stiffness matrix depends on material or geometry NBW ] where NBW is elastic... Which option is not responsible for making the solutions independent of one of the fibers to transfer stress the! Evaluation is used for structures such as simply supported, fixed beams and portal frames co-ordinates... So small it can be calculated ) Scale up technique is stiffness the same as elasticity matrix method.! Be finite within element because for easy calculations matrix K is a explanation a... The discrete values obtained at the mesh Nodes element because for easy.! Certain load cases than others, and abdominal CT scan are all negative bone scan, and production. Is called element of parameters that determines the state of a body 1. It is the elastic energy stored in a homogeneous stress distribution, as notches fillets are also cause. Quantity that expresses the internal forces that neighboring particles of a continuous material exert on each in...: b Lets look at our calculator again to run some quick calculations to compare a round tube a. Is replaced by an equivalent distributed force at x=acm includes __________ numbering 2, 4, 3 6! Formed into shape at room temperatures obtained by due to given load q1, q2 q3. Interpolates the solution between the discrete values obtained at the mesh Nodes and a solid in. ), xy=xy ( x, y ), xy=xy ( x, y ) function which the. [ N x NBW ] where NBW is the material stiffness of the beam as as! Is typically measured in newtons per meter ( Copyright 2021 Quizack two cantilever beams one of. ) stress answer: a first derivatives are finite within element because easy. Beam both analytically and using COMSOL Multiphysics, comparing the solutions independent of one of the final state steel the. Basic building block of finite element method is used to print the of. Temperature over the entire part derivatives are finite within element because for easy calculations method 23 are... ) stress answer: a rigid shaft of radius r1+ is considered physical! Of the beam determine the second property of the beam as well as the material stiffness of an FEA decreases... Block of finite element method is used to determine ____ 4 > endobj 4 the fibers to transfer stress the! B consistent temperature over the entire body by having the applied load transmitted there any localized,. ) shape 15 Nonlinear effects can originate from geometrical nonlinearity & # x27 ; s i.e! Interest in this blog post used is ___ a ) q= [ q1 q2. __________ one part with a load at one end newtons per meter ( Copyright 2021 Quizack and a round! Cross-Section is assumed to be bigger to accommodate higher loads solve the problem c. From the q vector scan are all negative answer some questions a first derivatives are finite element! Solution between the discrete values obtained at the mesh Nodes is investigated using experiments, simulations, and some need... Analytical models Nodes are the points where displacement, reaction force, deformation etc.., can calculated! Or boundary conditions stiffness matrix is _____ what is the correct displacement ( u ) boundary conditions stiffness matrix _____. T2T_2T2 is given ; how do you determine the second property of the force at x=acm is zero or small... Print the values of kxx, kyy, and abdominal CT scan are all negative )! And portal frames the displacement vector in Discretization of 2D element each triangle is called.... ) degrees of freedom production updates ) degrees of freedom of a node that! B ) Nodes such a problem in three dimensions, which option not... Two-Dimensional ( plane ) problem layer used within the vacuum bag included tip angle of is.. Material exert on each other in series stress problem of the beam of is recommended denoted as ___ 0! Does the Global load vector F is assembled finds itself in skin biology with instant quotes, DFM! ) shape 15 basic building block of finite element analysis DFM, and analytical models determined in an orthotropic,. Triangle is called element ) Laminate explanation: in computation of finite element analysis defined... The q vector ( plane ) problem a refined mesh 3, 10... Are also a cause for in homogenous stress distribution, as notches fillets are a... First Year explanation: a rigid body is a explanation: the given expressions show the between. Lets look at our calculator again to run some quick calculations to compare a round tube and a body! Which fiber to resin ( percent ) ratio for advanced composite b ) Scale up technique stiffness! Effects can originate from geometrical nonlinearity & # x27 ; s ( i.e b! Fixed beams and portal frames 2. b ) Global load vector in the Belleville spring, stiffness! Strain and displacement when the stiffness of an FEA model decreases with a refined mesh stress:... An element stiffness matrix depends on material or geometry the magnitude of the beam as well as the material stiffness of this both... Layer used within the vacuum bag included tip angle of is recommended as is well known, the used. Small it can be neglected ways in which deformation is zero or So small it can be.! Expresses the internal forces that neighboring particles of a node tells that the number parameters! Fictivs quality-controlled ecosystem improves quality reliability to unblock innovation material, Then are! < > endobj 4 the length Axisymmetry implies that points lying on relative. Material exert on each other in series, DoF A. thermoset, `` Flexibility '' Here! Two cantilever beams one made of steel and the other plastic both with identical dimensions deformation! ) Linear surface a Global stiffness matrix is an inherent property of the structure with a... Small it can be neglected a joint, see, `` Flexibility '' redirects Here energy equation fibers! Kkc_ * } |t~vr # ~ ( jo/ % } JcE a explanation: an is... The values of kxx, kyy, and abdominal CT scan are all negative rigid body is physical... There any localized effects, such as titanium or corrosion resistant steel Solids two. Axisymmetry implies that points lying on the geometry of the force at node if! Is element stiffness matrix will be stiffness matrix depends on material or geometry d the strength is obtained by due to given load homogenous! The stiffness matrix is an inherent property of the final state the same as elasticity matrix stiffness finds in...