The Tolerance of the Prestrain Update is Too Large

[YIDAN]

Hi,

I'm working with the open knee model to simulate the laxity tests with prestrain. However, when I added the prestrain to my model, I found the tolerance working in the update rule, is too large (more than 1), compared to the example given in plugin. I was wondering if it's sensible? I post part of my code below and attach .feb file here:https://drive.google.com/file/d/1NhT...ew?usp=sharing. This is the code for simulation of 10 Nm Valgus rotation. I hope you could give me some ideas/suggestions that if I misunderstood anything??

Also, I couldn't observe any difference between the simulation with an update and without an update, so I'm not sure if the large tolerance for update rule is sensible. Or, maybe I misuse the update rule? Any helps, I would appreciate it a lot!!

	<material id="11" name="acl" type="prestrain elastic">
		<density>1.5e-09</density>
		<prestrain type="in-situ stretch">
				<stretch>1.016</stretch>
				<isochoric>1</isochoric>
			</prestrain>
		<elastic type="trans iso Mooney-Rivlin">
			<c1>1.95</c1>
			<c2>0</c2>
			<c3>0.0139</c3>
			<c4>116.22</c4>
			<c5>535.039</c5>
			<lam_max>1.046</lam_max>
			<k>73.2</k>
			</elastic>
			<fiber type="local">     1,     4</fiber>
		</material>
		<material id="12" name="aclfiber" type="prestrain elastic">
			<density>1.5e-09</density>
			<prestrain type="in-situ stretch">
				<stretch>1.016</stretch>
				<isochoric>1</isochoric>
			</prestrain>
		<elastic type="trans iso Mooney-Rivlin">
			<c1>1.95</c1>
			<c2>0</c2>
			<c3>0.0139</c3>
			<c4>116.22</c4>
			<c5>535.039</c5>
			<lam_max>1.046</lam_max>
			<k>73.2</k>
			</elastic>
			<fiber type="local">     1,     4</fiber>
		</material>
		<material id="13" name="pcl" type="prestrain elastic">
			<density>1.5e-09</density>
			<prestrain type="in-situ stretch">
				<stretch>1.0</stretch>
				<isochoric>1</isochoric>
			</prestrain>
			<elastic type="trans iso Mooney-Rivlin">
			<c1>3.25</c1>
			<c2>0</c2>
			<c3>0.1196</c3>
			<c4>87.178</c4>
			<c5>431.063</c5>
			<lam_max>1.035</lam_max>
			<k>122</k>
			</elastic>
			<fiber type="local">     1,     4</fiber>
		</material>
		<material id="14" name="mcl" type="prestrain elastic">
			<density>1.5e-09</density>
			<prestrain type="in-situ stretch">
				<stretch>1.034</stretch>
				<isochoric>1</isochoric>
			</prestrain>
			<elastic type="trans iso Mooney-Rivlin">
			<c1>1.44</c1>
			<c2>0</c2>
			<c3>0.57</c3>
			<c4>48</c4>
			<c5>467.1</c5>
			<lam_max>1.063</lam_max>
			<k>397</k>
			</elastic>
			<fiber type="local">     1,     4</fiber>
		</material>
		<material id="15" name="lcl" type="prestrain elastic">
			<density>1.5e-09</density>
			<prestrain type="in-situ stretch">
				<stretch>1.027</stretch>
				<isochoric>1</isochoric>
			</prestrain>
			<elastic type="trans iso Mooney-Rivlin">
			<c1>1.44</c1>
			<c2>0</c2>
			<c3>0.57</c3>
			<c4>48</c4>
			<c5>467.1</c5>
			<lam_max>1.063</lam_max>
			<k>397</k>
			</elastic>
			<fiber type="local">     1,     4</fiber>
		</material>

<Constraints>
	<constraint type="prestrain">
        <tolerance>1.5</tolerance>
        </constraint>
	</Constraints>

Kind Regards,
Yidan