Unformatted text preview: ): Full Transient Dynamic Analysis (ANTYPE = 4) Element Type(s): Combination Elements (COMBIN40) Input Listing: vm83.dat Test Case
A block of weight WB is dropped from a height h onto a spring scale pan of weight WP. Determine the maximum
deflection δ of the pan and the maximum fall of the block y. Assume the impact to be perfectly plastic as a theoretical approximation. Figure 83.1 Spring Scale Problem Sketch Material Properties
k1 = 100 lb/in
WB = 50 lb
WP = 25 lb Geometric Properties
h = 6 ft = 72 in Loading
g = 386 in/sec2 ANSYS Verification Manual . ANSYS Release 9.0 . 002114 . © SAS IP, Inc. 1–187 VM83 Analysis Assumptions and Modeling Notes
The mass of the block (mB) and the mass of the pan (mP) are calculated as mB = WB/g = (50/386) lb-sec2/in and
mP = WP/g = (25/386) lb-sec2/in respectively. Deflection of the pan due to gravity is WP/k1 = 0.25 in, hence the
initial gap becomes (72-0.25) = 71.75 inches.
The spring length is chosen arbitrarily. The closed-gap spring constant (k2 = 10,000 lb/in) is arbitrarily selected
high enough to minimize t...
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