{VERSION 5 0 "SUN SPARC SOLARIS" "5.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Norma l" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 14 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Normal" -1 257 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {PARA 256 "" 0 "" {TEXT -1 9 "Math 2250" }}{PARA 256 "" 0 "" {TEXT -1 18 "Earthquake project" }}{PARA 257 "" 0 "" {TEXT -1 13 "Nove mber 2003" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 66 "Name _____________________________________ Class Time __________ " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 59 "Proje ct 3. Solve problems 3.1 to 3.6. The problem headers:" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 59 " _______ PROBLEM 3.1. BUILDING MODEL FOR AN EARTHQUAKE." }}{PARA 0 "" 0 "" {TEXT -1 67 " _______ PROBLEM 3.2. TABLE OF NATURAL FREQUENCIES AND PERIODS ." }}{PARA 0 "" 0 "" {TEXT -1 83 " _______ PROBLEM 3.3. UNDETERMIN ED COEFFICIENTS STEADY-STATE PERIODIC SOLUTION." }}{PARA 0 "" 0 "" {TEXT -1 46 " _______ PROBLEM 3.4. PRACTICAL RESONANCE." }}{PARA 0 "" 0 "" {TEXT -1 44 " _______ PROBLEM 3.5. EARTHQUAKE DAMAGE." } }{PARA 0 "" 0 "" {TEXT -1 38 " _______ PROBLEM 3.6. FIVE FLOORS." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "with(linalg):" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 " " {TEXT -1 38 "3.1. BUILDING MODEL FOR AN EARTHQUAKE." }}{PARA 0 "" 0 "" {TEXT -1 98 "Refer to the textbook of Edwards-Penney, section 7.4, \+ page 437. Consider a building with 7 floors." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 101 "Let the mass in slugs of each \+ story be m=1000.0 and let the spring constant be k=10000.0 (lbs/foot) ." }}{PARA 0 "" 0 "" {TEXT -1 94 "Define the 7 by 7 mass matrix M and \+ Hooke's matrix K for this system and convert Mx''=Kx into " }}{PARA 0 "" 0 "" {TEXT -1 74 "the system x''=Ax where A is defined by textbook equation (1) , page 437." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 " " 0 "" {TEXT -1 11 "PROBLEM 3.1" }}{PARA 0 "" 0 "" {TEXT -1 91 "Find t he eigenvalues of the matrix A to six digits, using the Maple command \+ \"eigenvals(A).\"" }}{PARA 0 "" 0 "" {TEXT -1 57 "Answer check: All s even eigenvalues should be negative. " }}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 0 "" 0 "" {TEXT -1 46 "# Sample Maple code for a model with \+ 4 floors." }}{PARA 0 "" 0 "" {TEXT -1 52 "# Use maple help to learn ab out evalf and eigenvals." }}{PARA 0 "" 0 "" {TEXT -1 74 " A := matrix( [ [-20,10,0,0], [10,-20,10,0], [0,10,-20,10], [0,0,10,-10]]);" }} {PARA 0 "" 0 "" {TEXT -1 24 " evalf(eigenvals(A),6); " }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "# Problem 3.1" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 46 "3.2. TABLE OF NATURAL FREQUENCIES AND PERIODS." }}{PARA 0 "" 0 "" {TEXT -1 33 "Refer to figure 7.4.17, page 437." }}{PARA 0 " " 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "PROBLEM 3.2." }} {PARA 0 "" 0 "" {TEXT -1 96 "Find the natural angular frequencies ome ga=sqrt(-lambda) for the seven story building and also " }}{PARA 0 "" 0 "" {TEXT -1 95 "the corresponding periods 2PI/omega, accurate to six digits. Display the answers in a table . " }}{PARA 0 "" 0 "" {TEXT -1 46 "The answers appear in Figure 7.4.17, page 437." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 32 "# Sample code for a 4 x3 table." }}{PARA 0 "" 0 "" {TEXT -1 48 "# Use maple help to learn a bout nops and printf." }}{PARA 0 "" 0 "" {TEXT -1 63 " ev:=[-10,-1.206 147582,-35.32088886,-23.47296354]: n:=nops(ev):" }}{PARA 0 "" 0 "" {TEXT -1 32 " Omega:=lambda -> sqrt(-lambda):" }}{PARA 0 "" 0 "" {TEXT -1 37 " format:=\"%10.6f %10.6f %10.6f\\n\": " }}{PARA 0 "" 0 "" {TEXT -1 62 " printf(\"%s %s %s\\n\",\"Eigenvalue\", \"Fr eq\",\"Period\");" }}{PARA 0 "" 0 "" {TEXT -1 72 " seq(printf(format,e v[i],Omega(ev[i]),2*evalf(Pi)/Omega(ev[i])),i=1..n);" }}{PARA 0 "" 0 " " {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "# Problem \+ 3.2" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}} {PARA 0 "" 0 "" {TEXT -1 62 "3.3. UNDETERMINED COEFFICIENTS STEADY-STA TE PERIODIC SOLUTION." }}{PARA 0 "" 0 "" {TEXT -1 95 "Consider the for ced equation x''=Ax+cos(wt)b where b is a constant vector. The ear thquake's" }}{PARA 0 "" 0 "" {TEXT -1 89 "ground vibration is account ed for by the extra term cos(wt)b, which has period T=2Pi/w." }} {PARA 0 "" 0 "" {TEXT -1 99 "The solution x(t) is the 7-vector of \+ excursions from equilibrium of the corresponding 7 floors." }}{PARA 0 "" 0 "" {TEXT -1 97 "Sought here is not the general solution, which ce rtainly contains transient terms, but rather the" }}{PARA 0 "" 0 "" {TEXT -1 93 "steady-state periodic solution, which is known from the t heory to have the form x(t)=cos(wt)c" }}{PARA 0 "" 0 "" {TEXT -1 80 "f or some vector c that depends only on A and b. See the textbook, \+ page 433." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "PROBLEM 3.3." }}{PARA 0 "" 0 "" {TEXT -1 98 "Define b:=0.25*w*w*v ector([1,1,1,1,1,1,1]): in Maple and find the vector c in the undet ermined" }}{PARA 0 "" 0 "" {TEXT -1 102 "coefficients solution x(t)=c os(wt)c. Vector c depends on w. As outlined in the textbook, vector \+ c " }}{PARA 0 "" 0 "" {TEXT -1 98 "can be found by solving the linear algebra problem -w^2 c = Ac + b; see page 433. Don't print c," }} {PARA 0 "" 0 "" {TEXT -1 71 "as it does not fit on one page; instead, \+ print c[1] as an illustration." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT -1 79 "# Sample code for defining b and A, then solving for c in the 4-floor case." }}{PARA 0 "" 0 "" {TEXT -1 52 "# See maple help to learn about vector and linsolve." }}{PARA 0 "" 0 "" {TEXT -1 46 " w:='w': u:=w*w: b:=0.25*u*vector([1,1,1,1]):" }} {PARA 0 "" 0 "" {TEXT -1 82 " Au:=matrix([ [-20+u,10,0,0], [10,-20+u, 10,0], [0,10,-20+u,10], [0,0,10,-10+u]]);" }}{PARA 0 "" 0 "" {TEXT -1 22 " c:=linsolve(Au,-b): " }}{PARA 0 "" 0 "" {TEXT -1 23 " 'c[1]'=ev alf(c[1],2);" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "# PROBLEM 3.3" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}} {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 24 "3.4 PRACT ICAL RESONANCE." }}{PARA 0 "" 0 "" {TEXT -1 100 "Consider the forced e quation x'=Ax+cos(wt)b of 3.3 above with b:=0.25*w*w*vector([1,1,1,1 ,1,1,1])." }}{PARA 0 "" 0 "" {TEXT -1 279 "Practical resonance can occ ur if a component of x(t) has large amplitude compared to the vector \nnorm of b. For example, an earthquake might cause a small 3-inch ex cursion on level ground, but\nthe building's floors might have 50-inch excursions, enough to destroy the building." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "PROBLEM 3.4." }}{PARA 0 "" 0 " " {TEXT -1 105 "Let Max(c) denote the maximum modulus of the component s of vector c. Plot g(T)=Max(c(w)) with w=(2*Pi)/T" }}{PARA 0 "" 0 " " {TEXT -1 106 "for periods T=0 to T=6, ordinates Max=0 to Max=10, the vector c(w) being the answer produced in 3.3 above." }}{PARA 0 "" 0 " " {TEXT -1 60 "Compare your figure to the textbook Figure 7.4.18, page 438." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 68 " # Sample maple code to define the function Max(c), 4-floor building." }}{PARA 0 "" 0 "" {TEXT -1 64 "# Use maple help to learn about norm, v ector, subs and linsolve." }}{PARA 0 "" 0 "" {TEXT -1 15 " with(linal g):" }}{PARA 0 "" 0 "" {TEXT -1 46 " w:='w': Max:= c -> norm(c,infini ty); u:=w*w:" }}{PARA 0 "" 0 "" {TEXT -1 32 " b:=0.25*w*w*vector([1,1 ,1,1]):" }}{PARA 0 "" 0 "" {TEXT -1 82 " Au:=matrix([ [-20+u,10,0,0], [10,-20+u,10,0], [0,10,-20+u,10], [0,0,10,-10+u]]);" }}{PARA 0 "" 0 " " {TEXT -1 38 " C:=ww -> subs(w=ww,linsolve(Au,-b)):" }}{PARA 0 "" 0 "" {TEXT -1 50 " plot(Max(C(2*Pi/r)),r=0..6,0..10,numpoints=150);" }} {PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 47 "# PROBLEM 3.4. WARNING: Save your file often!!!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 0 "" 0 "" {TEXT -1 23 "3.5. EARTHQUAKE DAMAGE." }}{PARA 0 " " 0 "" {TEXT -1 103 "The maximum amplitude plot of 3.4 can be used to \+ detect the likelihood of earthquake damage for a given" }}{PARA 0 "" 0 "" {TEXT -1 101 "ground vibration of period T. A ground vibration ( 1/4)cos(wt), T=2*Pi/w, will be assumed, as in 3.4." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "PROBLEM 3.5." }}{PARA 0 " " 0 "" {TEXT -1 106 "(a) Replot the amplitudes in 3.4 for periods 1.14 to 4 and amplitudes 5 to 10. There will be four spikes. " }}{PARA 0 " " 0 "" {TEXT -1 100 "(b) Create four zoom-in plots, one for each spike , choosing a T-interval that shows the full spike. " }}{PARA 0 "" 0 " " {TEXT -1 93 "(c) Determine from the four zoom-in plots approximate i ntervals for the period T such that " }}{PARA 0 "" 0 "" {TEXT -1 88 "some floor in the building will undergo excursions from equilibrium i n excess of 5 feet." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 " " {TEXT -1 85 "# Example: Zoom-in on a spike for amplitudes 5 feet to \+ 10 feet, periods 1.96 to 2.01." }}{PARA 0 "" 0 "" {TEXT -1 58 "with(li nalg): w:='w': Max:= c -> norm(c,infinity); u:=w*w:" }}{PARA 0 "" 0 " " {TEXT -1 80 "Au:=matrix([ [-20+u,10,0,0], [10,-20+u,10,0], [0,10,-20 +u,10], [0,0,10,-10+u]]);" }}{PARA 0 "" 0 "" {TEXT -1 30 "b:=0.25*w*w* vector([1,1,1,1]):" }}{PARA 0 "" 0 "" {TEXT -1 36 "C:=ww -> subs(w=ww, linsolve(Au,-b)):" }}{PARA 0 "" 0 "" {TEXT -1 55 "plot(Max(C(2*Pi/r)), r=1.96..2.01,5..10,numpoints=150);\n" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 46 "# PROBLEM 3.5. WARNING: Save your file often!!" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 40 "#(a) Plot four spikes on sep arate graphs" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "#(b) Plot f our zoom-in graphs." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "#(c) Print period ranges." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 1 " " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 17 "3.6. FIVE FLOORS." }}{PARA 0 "" 0 "" {TEXT -1 104 "Consider a b uilding with five floors each weighing 40 tons. Assume each floor corr esponds to a restoring" }}{PARA 0 "" 0 "" {TEXT -1 107 "Hooke's force \+ with constant k=5 tons/foot. Assume that ground vibrations from the ea rthquake are modeled by" }}{PARA 0 "" 0 "" {TEXT -1 68 "(1/4)cos(wt) w ith period T=2*Pi/w (same as the 7-floor model above)." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 12 "PROBLEM 3.6." }} {PARA 0 "" 0 "" {TEXT -1 212 "Model the 5-floor problem in Maple. Plot the maximum amplitudes against the period 1 to 15 and amplitude\n4 to 10. Determine from the graphic the period ranges which cause the ampl itude plot to spike above 4 feet." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT -1 110 "Sanity checks: Recall that a ton equals 2000 pounds, and that a pound of force equals mass (in slugs) times \+ " }}{PARA 0 "" 0 "" {TEXT -1 111 "the acceleration of gravity, 32 ft/s ec/sec. From this you can work out how to convert tons to slugs. You can " }}{PARA 0 "" 0 "" {TEXT -1 111 "check your reasoning on the ori ginal model, see text before equation (1) page 437. There are five sp ikes, but " }}{PARA 0 "" 0 "" {TEXT -1 36 "you may have to zoom in to \+ see them." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 46 "# PROBLEM 3.6. WARNING: Save your file often!!" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "# Define k, m and the 5x5 ma trix A." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 36 "# Amplitude plot for T=0..15,C=4..10" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "# P lot five zoom-in graphs" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 169 "# From the graphics, five T-ranges give amplitude\n# spikes above 4 f eet. These are determined by left \n# mouse-clicks on the graph, so th ey are approximate values only. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}} {MARK "149 0 0" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }