Conducting a fragility test 3. Plot the damage boundary curve by connecting the vertical velocity boundary line and the horizontal acceleration boundary line. 4. Notes: In a rigorous testing program, damage boundary curves are generated for each orientation of the unit. Compromises are often made to limit the number of units which must be damaged. Figure 14.4 Damage boundary line developmentConducting a fragility test 3. Plot the damage boundary curve by connecting the vertical velocity boundary line and the horizontal acceleration boundary line. 4. Notes: In a rigorous testing program, damage boundary curves are generated for each orientation of the unit. Compromises are often made to limit the number of units which must be damaged. Figure 14.4 Damage boundary line development